CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present disclosure is generally directed to compounds which can inhibit adaptor
associated kinase 1 (AAK1), compositions comprising such compounds, and methods for
inhibiting AAK1.
[0002] Adaptor associated kinase 1 (AAK1) is a member of the Ark1/Prk1 family of serine/threonine
kinases. AAK1 mRNA exists in two splice forms termed short and long. The long form
predominates and is highly expressed in brain and heart (
Henderson and Conner, Mol. Biol. Cell. 2007, 18, 2698-2706). AAK1 is enriched in synaptosomal preparations and is co-localized with endocytic
structures in cultured cells. AAK1 modulates clatherin coated endocytosis, a process
that is important in synaptic vesicle recycling and receptor-mediated endocytosis.
AAK1 associates with the AP2 complex, a hetero-tetramer which links receptor cargo
to the clatherin coat. The binding of clatherin to AAK1 stimulates AAK1 kinase activity
(
Conner et. al., Traffic 2003, 4, 885-890;
Jackson et. al., J. Cell. Biol. 2003, 163, 231-236). AAK1 phosphorylates the mu-2 subunit of AP-2, which promotes the binding of mu-2
to tyrosine containing sorting motifs on cargo receptors (
Ricotta et. al., J. Cell Bio. 2002, 156, 791-795;
Conner and Schmid, J. Cell Bio. 2002, 156, 921-929). Mu2 phosphorylation is not required for receptor uptake, but phosphorylation enhances
the efficiency of internalization (
Motely et. al., Mol. Biol. Cell. 2006, 17, 5298-5308).
[0003] AAK1 has been identified as an inhibitor of Neuregulin-1/ErbB4 signaling in PC 12
cells. Loss of AAK1 expression through RNA interference mediated gene silencing or
treatment with the kinase inhibitor K252a (which inhibits AAK1 kinase activity) results
in the potentiation of Neuregulin-1 induced neurite outgrowth. These treatments result
in increased expression of ErbB4 and accumulation of ErbB4 in or near the plasma membrane
(
Kuai et. al., Chemistry and Biology 2011, 18, 891-906). NRG1 and ErbB4 are putative schizophrenia susceptibility genes (
Buonanno, Brain Res. Bull. 2010, 83, 122-131). SNPs in both genes have been associated with multiple schizophrenia endophenotypes
(
Greenwood et. al., Am. J. Psychiatry 2011, 168, 930-946). Neuregulin 1 and ErbB4 KO mouse models have shown schizophrenia relevant morphological
changes and behavioral phenotypes (
Jaaro-Peled et. al., Schizophrenia Bulletin 2010, 36, 301-313;
Wen et. al., Proc. Natl. Acad. Sci. USA. 2010, 107, 1211-1216). In addition, a single nucleotide polymorphism in an intron of the AAK1 gene has
been associated with the age of onset of Parkinson's disease (
Latourelle et. al., BMC Med. Genet. 2009, 10, 98). These results suggest that inhibition of AAK1 activity may have utility in the
treatment of schizophrenia, cognitive deficits in schizophrenia, Parkinson's disease,
neuropathic pain, bipolar disorder, and Alzheimer's disease.
[0004] In a first aspect the present disclosure provides a compound of formula (I)

or a pharmaceutically acceptable salt thereof, wherein:
R1 is selected from hydrogen, C2-C4alkenyl, C1-C3alkoxy, C1-C3alkoxyC1-C3alkyl, C1-C3alkyl, C1-C3alkylamino, arylC1-C3alkyl, C3-C6cycloalkyl, C3-C6cycloalkylC1-C3alkyl, C1-C3haloalkyl, and C1-C3hydroxyalkyl;
R2 is selected from hydrogen, C1-C3alkoxy, C1-C3alkoxycarbonylamino, C1-C3alkyl, C1-C3alkylamino, C1-C3alkylcarbonylamino, amino, arylamino, arylcarbonylamino, C3-C6cycloalkylamino, C3-C6cycloalkylcarbonylamino, C3-C6cycloalkyloxy, halo, C1-C3haloalkoxy, C1-C3haloalkyl, C2-C3haloalkylamino, C2-C3haloalkylcarbonylamino, hydroxy, and phenylC1-C3alkylamino, wherein the phenyl is optionally substituted with a C1-C3alkoxy group;
R3 and R4 are independently selected from hydrogen, C1-C4alkoxy, C1-C3alkoxyC1-C3alkyl, C1-C3alkoxycarbonyl, C1-C4alkyl, C1-C3alkylsulfonyl, aminocarbonyl, cyano, C3-C6cycloalkyl, di(C1-C3alkyl)aminocarbonyl, halo, C1-C3haloalkoxy, C1-C3haloalkyl, heteroaryl, hydroxy, C1-C3hydroxyalkyl, and phenyl optionally substituted with a halo group;
R5 is C1-C3alkyl-Y or C2-C8alkyl, wherein the C2-C8alkyl is optionally substituted with one, two, three, or four groups independently
selected from C1-C3alkoxy, C1-C3alkylamino, C1-C3alkoxyC2-C3alkylamino, amino, aryl, di(C1-C3alkyl)amino, halo, C1-C3haloalkylamino, C1-C3haloalkylcarbonylamino, hydroxy, - NRxRy, and C1-C8cycloalkyl, wherein the cycloalkyl is further optionally substituted with one, two,
or three groups independently selected from C1-C3alkoxy, C1-C3alkyl, C1-C3alkylamino, C1-C3alkoxyC2-C3alkylamino, amino, aryl, arylC1-C3alkyl, halo, C1-C3haloalkyl, C1-C3haloalkylamino and hydroxy;
Rx and Ry, together with the nitrogen atom to which they are attached, form a three- to six-membered
ring; and
Y is selected from

wherein n is 0, 1, 2, or 3;
each R6 is independently selected from hydrogen, C1-C6alkyl, aryl, arylC1-C3alkyl, C3-C6cycloalkyl, halo, and C1-C3haloalkyl;
each R7 is independently selected from hydrogen, C1-C3alkoxy and hydroxy; and
R8 is selected from hydrogen, C1-C6alkyl, C3-C6cycloalkyl, and C1-C6alkylcarbonyl.
[0005] In a first embodiment of the first aspect the present disclosure provides a compound
of formula (I) wherein R
5 is C
2-C
8alkyl, wherein the C
2-C
8alkyl is optionally substituted with one, two, three, or four groups independently
selected from C
1-C
3alkoxy, amino, C
1-C
3alkylamino, di(C
1-C
3alkyl)amino, halo, and C
3-C
8cycloalkyl; or R
5 is C
1-C
3alkyl-Y wherein Y is

wherein R
6, R
7, and R
8 are hydrogen.
[0006] In a second embodiment of the first aspect the present disclosure provides a compound
of formula (I) wherein R
5 is C
2-C
8alkyl optionally substituted with one, two, three, or four groups independently selected
from amino and halo.
[0007] In a third embodiment of the first aspect the present disclosure provides a compound
of formula (I) wherein R
1 is selected from hydrogen, C
2-C
4alkenyl, C
1-C
3alkoxyC
1-C
3alkyl, C
1-C
3alkyl, arylC
1-C
3alkyl, C
3-C
6cycloalkylC
1-C
3alkyl, C
1-C
3haloalkyl, and C
1-C
3hydroxyalkyl;
R
2 is selected from hydrogen, C
1-C
3alkoxy, C
1-C
3alkyl, C
1-C
3alkylcarbonylamino, amino, halo, C
1-C
3haloalkyl, and phenylC
1-C
3alkylamino, wherein the phenyl is optionally substituted with a C
1-C
3alkoxy group;
R
3 and R
4 are independently selected from hydrogen, C
1-C
4alkoxy, C
1-C
3alkoxyC
1-C
3alkyl, C
1-C
3alkoxycarbonyl, C
1-C
4alkyl, C
1-C
3alkylsulfonyl, aminocarbonyl, cyano, C
3-C
6cycloalkyl, di(C
1-C
3alkyl)aminocarbonyl, halo, C
1-C
3haloalkoxy, C
1-C
3haloalkyl, heteroaryl, hydroxy, C
1-C
3hydroxyalkyl, and phenyl optionally substituted with a halo group;
R
5 is C
1-C
3alkyl-Y or C
2-C
8alkyl, wherein the C
2-C
8alkyl is optionally substituted with one, two, three, or four groups independently
selected from C
1-C
3alkoxy, C
1-C
3alkylamino, amino, di(C
1-C
3alkyl)amino, halo, and C
3-C
8cycloalkyl; and wherein Y is selected from

wherein R
6, R
7, and R
8 are hydrogen.
[0008] In a second aspect the present disclosure provides a compound of formula (II)

or a pharmaceutically acceptable salt thereof, wherein:
R1 is selected from hydrogen, C2-C4alkenyl, C1-C3alkoxy, C1-C3alkoxy C1-C3alkyl, C1-C3alkyl, C1-C3alkylamino, arylC1-C3alkyl, C3-C6cycloalkyl, C3-C6cycloalkylC1-C3alkyl, and C1-C3haloalkyl;
R2 is selected from hydrogen, C1-C3alkoxy, C1-C3alkoxycarbonylamino, C1-C3alkyl, C1-C3alkylamino, C1-C3alkylcarbonylamino, amino, arylamino, arylcarbonylamino, C3-C6cycloalkylamino, C3-C6cycloalkylcarbonylamino, C3-C6cycloalkyloxy, halo, C1-C3haloalkoxy, C1-C3haloalkyl, C2-C3haloalkylamino, C2-C3haloalkylcarbonylamino, and hydroxy;
R3 and R4 are independently selected from hydrogen, C1-C4alkyl, cyano, C3-C6cycloalkyl, halo, C1-C3haloalkyl, and hydroxy;
R5 is C1-C3alkyl-Y or C2-C8alkyl, wherein the C2-C8alkyl is optionally substituted with one, two, or three groups independently selected
from C1-C3alkoxy, C1-C3alkylamino, C1-C3alkoxyC2-C3alkylamino, amino, aryl, halo, C1-C3haloalkylamino, C1-C3haloalkylcarbonylamino, hydroxy, -NRxRy, and C3-C8cycloalkyl, wherein the cycloalkyl is further optionally substituted with one, two,
or three groups independently selected from C1-C3alkoxy, C1-C3alkyl, C1-C3alkylamino, C1-C3alkoxyC2-C3alkylamino, amino, aryl, arylC1-C3alkyl, halo, C1-C3haloalkyl, C1-C3haloalkylamino and hydroxy;
Rx and Ry, together with the nitrogen atom to which they are attached, form a three- to six-membered
ring; and
Y is selected from

wherein n is 0, 1, 2, or 3;
each R6 is independently selected from hydrogen, C1-C6alkyl, aryl, arylC1-C3alkyl, C3-C6cycloalkyl, halo, and C1-C3haloalkyl;
each R7 is independently selected from hydrogen, C1-C3alkoxy and hydroxy; and
R8 is selected from hydrogen, C1-C6alkyl, C3-C6cycloalkyl, and C1-C6alkylcarbonyl.
[0009] In a first embodiment of the second aspect the present disclosure provides a compound
of formula (I), or a pharmaceutically acceptable salt thereof, wherein R
5 is C
2-C
8alkyl optionally substituted with one, two, or three groups independently selected
from C
1-C
3alkoxy, C
1-C
3alkylamino, C
1-C
3alkoxyC
2-C
3alkylamino, amino, aryl, halo, C
1-C
3haloalkylamino, C
1-C
3haloalkylcarbonylamino, hydroxy, -NR
xR
y, and C
3-C
8cycloalkyl, wherein the cycloalkyl is further optionally substituted with one, two,
or three groups independently selected from C
1-C
3alkoxy, C
1-C
3alkyl, C
1-C
3alkylamino, C
1-C
3alkoxyC
2-C
3alkylamino, amino, aryl, arylC
1-C
3alkyl, halo, C
1-C
3haloalkyl, C
1-C
3haloalkylamino and hydroxy. In a second embodiment of the second aspect R
5 is C
2-C
8alkyl optionally substituted with one, two, or three groups independently selected
from amino and halo.
[0010] In a third embodiment of the second aspect the present disclosure provides a compound
of formula (I), or a pharmaceutically acceptable salt thereof, wherein R
1 is selected from hydrogen, C
2-C
4alkenyl, C
1-C
3alkoxyC
1-C
3alkyl, C
1-C
3alkyl, arylC
1-C
3alkyl, and C
3-C
6cycloalkylC
1-C
3alkyl;
[0011] R
2 is selected from hydrogen, C
1-C
3alkyl, C
1-C
3alkylcarbonylamino, and amino;
[0012] R
3 and R
4 are independently selected from hydrogen, C
1-C
4alkyl, cyano, C
3-C
6cycloalkyl, halo, and hydroxy; and
[0013] R
5 is C
2-C
8alkyl optionally substituted with one, two, or three groups independently selected
from amino and halo.
[0014] In a third aspect the present disclosure provides composition comprising a pharmaceutically
acceptable amount of a compound of formula (I), or a pharmaceutically acceptable salt
thereof, and a pharmaceutically acceptable carrier.
[0015] In a fourth aspect the present disclosure provides a method of inhibiting adaptor
associated kinase 1 (AAK1) activity, comprising contacting AAK1 with a compound of
formula (I), or a pharmaceutically acceptable salt thereof.
[0016] In a fifth aspect the present disclosure provides a method for treating or managing
a disease or a disorder mediated by AAK1 activity, the method comprising administering
to a patient in need thereof a therapeutically effective amount of a compound of formula
(I), or a pharmaceutically acceptable salt thereof. In a first embodiment of the fifth
aspect the disease or disorder is selected from Alzheimer's disease, bipolar disorder,
pain, Parkinson's disease, and schizophrenia. In a second embodiment of the fifth
aspect the pain is neuropathic pain. In a third embodiment of the fifth aspect the
neuropathic pain is fibromyalgia or peripheral neuropathy.
[0017] Other aspects of the present disclosure may include suitable combinations of embodiments
disclosed herein.
[0018] Yet other aspects and embodiments may be found in the description provided herein.
BRIEF DESCRIPTION OF THE FIGURES
[0019] Aspects of the disclosure are illustrated in Figure 1, which shows results obtained
from a formalin pain model using AAK1 homozygous (-/-) knockout mice and their wild-type
(+/+) littermates. The AAK1 homozygous (-/-) knockout mice show a clear reduction
in both acute and tonic pain response as compared to their wild-type (+/+) littermates.
[0020] This disclosure is based, in part, on the discovery that AAK1 knockout mice exhibit
a high resistance to pain. That discovery prompted research that ultimately led to
the discovery of AAK1 inhibitors, compositions comprising them, and methods of their
use.
[0021] The description of the present disclosure herein should be construed in congruity
with the laws and principals of chemical bonding. In some instances it may be necessary
to remove a hydrogen atom in order to accommodate a substituent at any given location.
[0022] It should be understood that the compounds encompassed by the present disclosure
are those that are suitably stable for use as pharmaceutical agent.
[0023] It is intended that the definition of any substituent or variable at a particular
location in a molecule be independent of its definitions elsewhere in that molecule.
For example, when n is 2, each of the two R
6 groups may be the same or different.
[0024] As used in the present specification, the following terms have the meanings indicated:
[0025] As used herein, the singular forms "a", "an", and "the" include plural reference
unless the context clearly dictates otherwise.
[0026] In some instances, the number of carbon atoms in any particular group is denoted
before the recitation of the group. For example, the term "C
1-6 alkyl" denotes an alkyl group containing one to six carbon atoms. Where these designations
exist they supercede all other definitions contained herein.
[0027] The term "alkenyl," as used herein, refers to a straight or branched chain group
containing at least one carbon-carbon double bond.
[0028] The term "alkoxy," as used herein, refers to an alkyl group attached to the parent
molecular moiety through an oxygen atom.
[0029] The term "alkoxyalkyl," as used herein, refers to an alkyl group substituted with
one, two, or three alkoxy groups.
[0030] The term "alkoxyalkylamino," as used herein, refers to -NHR wherein R is an alkoxyalkyl
group.
[0031] The term "alkoxycarbonyl," as used herein, refers to an alkoxy group attached to
the parent molecular moiety through a carbonyl group.
[0032] The term "alkoxycarbonylamino," as used herein, refers to an -NHR wherein R is an
alkoxycarbonyl group.
[0033] The term "alkyl," as used herein, refers to a group derived from a straight or branched
chain saturated hydrocarbon.
[0034] The term "alkylamino," as used herein refers to -NHR, wherein R is an alkyl group.
[0035] The term "alkylcarbonyl," as used herein, refers to an alkyl group attached to the
parent molecular moiety through a carbonyl group.
[0036] The term "alkylcarbonylamino," as used herein, refers to -NHR wherein R is an alkylcarbonyl
group.
[0037] The term "alkylsulfonyl," as used herein, refers to an alkyl group attached to the
parent molecular moiety through a sulfonyl group.
[0038] The term "amino," as used herein, refers to -NH
2.
[0039] The term "aminocarbonyl," as used herein, refers to -C(O)NH
2.
[0040] The term "aryl," as used herein, refers to a phenyl group, or a bicyclic fused ring
system wherein one or both of the rings is a phenyl group. Bicyclic fused ring systems
consist of a phenyl group fused to a four- to six-membered aromatic or nonaromatic
carbocyclic ring. The aryl groups of the present invention can be attached to the
parent molecular moiety through any substitutable carbon atom in the group. Representative
examples of aryl groups include, but are not limited to, indanyl, indenyl, naphthyl,
phenyl, and tetrahydronaphthyl.
[0041] The term "arylalkyl," as used herein, refers to an alkyl group substituted with one,
two, or three aryl groups.
[0042] The term "arylamino," as used herein, refers to -NHR wherein R is an aryl group.
[0043] The term "arylcarbonyl," as used herein, refers to an aryl group attached to the
parent molecular moiety through a carbonyl group.
[0044] The term "arylcarbonylamino," as used herein refers to -NHR wherein R is an arylcarbonyl
group.
[0045] The term "carbonyl," as used herein, refers to -C(O)-.
[0046] The term "cyano," as used herein, refers to -CN.
[0047] The term "cycloalkyl," as used herein, refers to a saturated monocyclic hydrocarbon
ring system having zero heteroatoms. Representative examples of cycloalkyl groups
include, but are not limited to, cyclopropyl, cyclopentyl, and cyclohexyl.
[0048] The term "(cycloalkyl)alkyl," as used herein, refers to an alkyl group substituted
with one, two, or three cycloalkyl groups.
[0049] The term "cycloalkylamino," as used herein, refers to -NHR wherein R is a cycloalkyl
group.
[0050] The term "cycloalkylcarbonyl," as used herein, refers to a cycloalkyl group attached
to the parent molecular moiety through a carbonyl group.
[0051] The term "cycloalkylcarbonylamino," as used herein, refers to -NHR wherein R is a
cycloalkylcarbonyl group.
[0052] The term "cycloalkyloxy," as used herein, refers to a cycloalkyl group attached to
the parent molecular moiety through an oxygen atom.
[0053] The term "dialkylamino," as used herein, refers to -NR
2 wherein R is alkyl. The two R groups may be the same or different.
[0054] The term "dialkylaminocarbonyl," as used herein, refers to -C(O)NR
2, wherein R is alkyl. The two R groups may be the same or different.
[0055] The term "halo," as used herein, refers to Br, Cl, F, and/or I.
[0056] The term "haloalkoxy," as used herein, refers to a haloalkyl group attached to the
parent molecular moiety through an oxygen atom.
[0057] The term "haloalkyl," as used herein, refers to an alkyl group substituted by one,
two, three, or four halogen atoms.
[0058] The term "haloalkylamino," as used herein, refers to -NHR wherein R is a haloalkyl
group.
[0059] The term "haloalkylcarbonyl," as used herein, refers to a haloalkyl group attached
to the parent molecular moiety through a carbonyl group.
[0060] The term "haloalkylcarbonylamino," as used herein, refers to -NHR wherein R is a
haloalkylcarbonyl group.
[0061] The term "heteroaryl," as used herein, refers to a five- or six-membered aromatic
ring containing one or two heteroatoms independently selected from nitrogen, oxygen,
and sulfur.
[0062] The term "hydroxy," as used herein, refers to -OH.
[0063] The term "hydroxyalkyl," as used herein, refers to an alkyl group substituted with
one, two, or three hydroxy groups.
[0064] The term "phenylalkylamino" as used herein, refers to -NHR, wherein R is a phenylalkylgroup.
[0065] The term "sulfonyl," as used herein, refers to -SO
2.
[0066] Asymmetric centers may exist in the compounds of the present disclosure. It should
be understood that the disclosure encompasses all stereochemical isomeric forms, or
mixtures thereof, which possess the ability to inhibit AAK1. Individual stereoisomers
of compounds can be prepared synthetically from commercially available starting materials
which contain chiral centers or by preparation of mixtures of enantiomeric products
followed by separation such as conversion to a mixture of diastereomers followed by
separation or recrystallization, chromatographic techniques, or direct separation
of enantiomers on chiral chromatographic columns. Starting compounds of particular
stereochemistry are either commercially available or can be made and resolved by techniques
known in the art.
[0067] Certain compounds of the present disclosure may also exist in different stable conformational
forms which may be separable. Torsional asymmetry due to restricted rotation about
an asymmetric single bond, for example because of steric hindrance or ring strain,
may permit separation of different conformers. The present disclosure includes each
conformational isomer of these compounds and mixtures thereof.
[0068] The term "compounds of the present disclosure", and equivalent expressions, are meant
to embrace compounds of formula (I), and pharmaceutically acceptable enantiomers,
diastereomers, and salts thereof. Similarly, references to intermediates are meant
to embrace their salts where the context so permits.
[0069] The present disclosure is intended to include all isotopes of atoms occurring in
the present compounds. Isotopes include those atoms having the same atomic number
but different mass numbers. By way of general example and without limitation, isotopes
of hydrogen include deuterium and tritium. Isotopes of carbon include
13C and
14C. Isotopically-labeled compounds of the disclosure can generally be prepared by conventional
techniques known to those skilled in the art or by processes analogous to those described
herein, using an appropriate isotopically-labeled reagent in place of the non-labeled
reagent otherwise employed. Such compounds may have a variety of potential uses, for
example as standards and reagents in determining biological activity. In the case
of stable isotopes, such compounds may have the potential to favorably modify biological,
pharmacological, or pharmacokinetic properties.
[0070] The compounds of the present disclosure can exist as pharmaceutically acceptable
salts. The term "pharmaceutically acceptable salt," as used herein, represents salts
or zwitterionic forms of the compounds of the present disclosure which are water or
oil-soluble or dispersible, which are, within the scope of sound medical judgment,
suitable for use in contact with the tissues of patients without excessive toxicity,
irritation, allergic response, or other problem or complication commensurate with
a reasonable benefit/risk ratio, and are effective for their intended use. The salts
can be prepared during the final isolation and purification of the compounds or separately
by reacting a suitable nitrogen atom with a suitable acid. Representative acid addition
salts include acetate, adipate, alginate, citrate, aspartate, benzoate, benzenesulfonate,
bisulfate, butyrate, camphorate, camphorsulfonate; digluconate, dihydrobromide, diydrochloride,
dihydroiodide, glycerophosphate, hemisulfate, heptanoate, hexanoate, formate, fumarate,
hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate,
mesitylenesulfonate, methanesulfonate, naphthylenesulfonate, nicotinate, 2-naphthalenesulfonate,
oxalate, palmoate, pectinate, persulfate, 3-phenylproprionate, picrate, pivalate,
propionate, succinate, tartrate, trichloroacetate, trifluoroacetate, phosphate, glutamate,
bicarbonate, para-toluenesulfonate, and undecanoate. Examples of acids which can be
employed to form pharmaceutically acceptable addition salts include inorganic acids
such as hydrochloric, hydrobromic, sulfuric, and phosphoric, and organic acids such
as oxalic, maleic, succinic, and citric.
[0071] Basic addition salts can be prepared during the final isolation and purification
of the compounds by reacting a carboxy group with a suitable base such as the hydroxide,
carbonate, or bicarbonate of a metal cation or with ammonia or an organic primary,
secondary, or tertiary amine. The cations of pharmaceutically acceptable salts include
lithium, sodium, potassium, calcium, magnesium, and aluminum, as well as nontoxic
quaternary amine cations such as ammonium, tetramethylammonium, tetraethylammonium,
methylamine, dimethylamine, trimethylamine, triethylamine, diethylamine, ethylamine,
tributylamine, pyridine, N,N-dimethylaniline, N-methylpiperidine, N-methylmorpholine,
dicyclohexylamine, procaine, dibenzylamine, N,N-dibenzylphenethylamine, and N,N'-dibenzylethylenediamine.
Other representative organic amines useful for the formation of base addition salts
include ethylenediamine, ethanolamine, diethanolamine, piperidine, and piperazine.
One embodiment of this disclosure encompasses methods of inhibiting adaptor associated
kinase 1 (AAK1), both
in vitro and
in vivo, which comprise contacting AAK1 with a compound of formula I or a pharmaceutically
acceptable salt thereof.
[0072] When it is possible that, for use in therapy, therapeutically effective amounts of
a compound of formula (I), as well as pharmaceutically acceptable salts thereof, may
be administered as the raw chemical, it is possible to present the active ingredient
as a pharmaceutical composition. Accordingly, the disclosure further provides pharmaceutical
compositions, which include therapeutically effective amounts of compounds of formula
(I) or pharmaceutically acceptable salts thereof, and one or more pharmaceutically
acceptable carriers, diluents, or excipients. Unless otherwise indicated, a "therapeutically
effective amount" of a compound is an amount sufficient to provide a therapeutic benefit
in the treatment or management of a disease or condition, or to delay or minimize
one or more symptoms associated with the disease or condition. The term "therapeutically
effective amount" can encompass an amount that improves overall therapy, reduces or
avoids symptoms or causes of a disease or condition, or enhances the therapeutic efficacy
of another therapeutic agent.
[0073] The term "therapeutically effective amount," as used herein, refers to an amount
of a compound or compounds sufficient to provide a therapeutic benefit in the treatment
or management of a disease or condition, or to delay or minimize one or more symptoms
associated with the disease or condition. A "therapeutically effective amount" of
a compound means an amount of therapeutic agent, alone or in combination with other
therapies, that provides a therapeutic benefit in the treatment or management of the
disease or condition. The term "therapeutically effective amount" can encompass an
amount that improves overall therapy, reduces or avoids symptoms or causes of a disease
or condition, or enhances the therapeutic efficacy of another therapeutic agent. When
applied to an individual active ingredient, administered alone, the term refers to
that ingredient alone. When applied to a combination, the term refers to combined
amounts of the active ingredients that result in the therapeutic effect, whether administered
in combination, serially, or simultaneously. The compounds of formula (I) and pharmaceutically
acceptable salts thereof, are as described above. The carrier(s), diluent(s), or excipient(s)
must be acceptable in the sense of being compatible with the other ingredients of
the formulation and not deleterious to the recipient thereof. In accordance with another
aspect of the present disclosure there is also provided a process for the preparation
of a pharmaceutical formulation including admixing a compound of formula (I), or a
pharmaceutically acceptable salt thereof, with one or more pharmaceutically acceptable
carriers, diluents, or excipients. The term "pharmaceutically acceptable," as used
herein, refers to those compounds, materials, compositions, and/or dosage forms which
are, within the scope of sound medical judgment, suitable for use in contact with
the tissues of patients without excessive toxicity, irritation, allergic response,
or other problem or complication commensurate with a reasonable benefit/risk ratio,
and are effective for their intended use.
[0074] Pharmaceutical formulations may be presented in unit dose forms containing a predetermined
amount of active ingredient per unit dose. Dosage levels of between about 0.01 and
about 250 milligram per kilogram ("mg/kg") body weight per day, preferably between
about 0.05 and about 100 mg/kg body weight per day of the compounds of the present
disclosure are typical in a monotherapy for the prevention and treatment of disease.
Typically, the pharmaceutical compositions of this disclosure will be administered
from about 1 to about 5 times per day or alternatively, as a continuous infusion.
Such administration can be used as a chronic or acute therapy. The amount of active
ingredient that may be combined with the carrier materials to produce a single dosage
form will vary depending on the condition being treated, the severity of the condition,
the time of administration, the route of administration, the rate of excretion of
the compound employed, the duration of treatment, and the age, gender, weight, and
condition of the patient. Preferred unit dosage formulations are those containing
a daily dose or sub-dose, as herein above recited, or an appropriate fraction thereof,
of an active ingredient. Treatment may be initiated with small dosages substantially
less than the optimum dose of the compound. Thereafter, the dosage is increased by
small increments until the optimum effect under the circumstances is reached. In general,
the compound is most desirably administered at a concentration level that will generally
afford effective results without causing any harmful or deleterious side effects.
[0075] When the compositions of this disclosure comprise a combination of a compound of
the present disclosure and one or more additional therapeutic or prophylactic agent,
both the compound and the additional agent are usually present at dosage levels of
between about 10 to 150%, and more preferably between about 10 and 80% of the dosage
normally administered in a monotherapy regimen.
[0076] Compounds of the disclosure may be administered in combination with one or more additional
therapeutic or prophylactic agents. For example, when used for the treatment of pain,
possible additional agents include immunosuppressive agents, anti-inflammatory agents,
and/or other agents used in the treatment of pain.
[0077] Immunosuppressants suitable for use in the methods and compositions of this disclosure
include those known in the art. Examples include aminopterin, azathioprine, cyclosporin
A, D-penicillamine, gold salts, hydroxychloroquine, leflunomide, methotrexate, minocycline,
rapamycin, sulfasalazine, tacrolimus (FK506), and pharmaceutically acceptable salts
thereof. A particular immunosuppressant is methotrexate.
[0078] Additional examples of immunosuppressants include anti-TNF antibodies, such as adalimumab,
certolizumab pegol, etanercept, and infliximab. Others include interleukin-1 blockers,
such as anakinra. Others include anti-B cell (CD20) antibodies, such as rituximab.
Others include T cell activation blockers, such as abatacept.
[0079] Other immunosuppressants include inosine monophosphate dehydrogenase inhibitors,
such as mycophenolate mofetil (CellCept®) and mycophenolic acid (Myfortic®).
[0080] Anti-inflammatory drugs suitable for use in the methods and compositions of this
disclosure include those known in the art. Examples include glucocorticoids and NSAIDs.
Examples of glucocorticoids include aldosterone, beclometasone, betamethasone, cortisone,
deoxycorticosterone, dexamethasone, fludrocortisones, hydrocortisone, methylprednisolone,
prednisolone, prednisone, triamcinolone, and pharmaceutically acceptable salts thereof.
[0081] Examples ofNSAID include salicylates (
e.g., aspirin, amoxiprin, benorilate, choline magnesium salicylate, diflunisal, faislamine,
methyl salicylate, magnesium salicylate, salicyl salicylate, and pharmaceutically
acceptable salts thereof), arylalkanoic acids (e.g., diclofenac, aceclofenac, acemetacin,
bromfenac, etodolac, indometacin, nabumetone, sulindac, tolmetin, and pharmaceutically
acceptable salts thereof), arylpropionic acids (
e.g., ibuprofen, carprofen, fenbufen, fenoprofen, flurbiprofen, ketoprofen, ketorolac,
loxoprofen, naproxen, oxaprozin, tiaprofenic acid, suprofen, and pharmaceutically
acceptable salts thereof), arylanthranilic acids (
e.g., meclofenamic acid, mefenamic acid, and pharmaceutically acceptable salts thereof),
pyrazolidine derivatives (
e.g., azapropazone, metamizole, oxyphenbutazone, phenylbutazone, sulfinprazone, and pharmaceutically
acceptable salts thereof), oxicams (
e.g., lornoxicam, meloxicam, piroxicam, tenoxicam, and pharmaceutically acceptable salts
thereof), COX-2 inhibitors (
e.g., celecoxib, etoricoxib, lumiracoxib, parecoxib, rofecoxib, valdecoxib, and pharmaceutically
acceptable salts thereof), and sulphonanilides (
e.g., nimesulide and pharmaceutically acceptable salts thereof).
[0082] Other agents used in the treatment of pain (including but not limited to neuropathic
and inflammatory pain) include, but are not limited to, agents such as pregabalin,
lidocaine, duloxetine, gabapentin, carbamazepine, capsaicin, and other serotonin/norepinephrine/dopamine
reuptake inhibitors, and opiates (such as oxycontin, morphine, and codeine).
[0083] In the treatment of pain caused by a known disease or condition, such as diabetes,
infection (
e.g., herpes zoster or HIV infection), or cancer, compounds of the disclosure may be administered
in combination with one or more additional therapeutic or prophylactic agents directed
at the underlying disease or condition. For example, when used to treat diabetic neuropathy,
compounds of the disclosure may be administered in combination with one or more anti-diabetic
agents, antihyperglycemic agents, hypolipidemic/lipid lowering agents, anti-obesity
agents, antihypertensive agents and appetite suppressants. Examples of anti-diabetic
agents include biguanides (
e.g., metformin, phenformin), glucosidase inhibitors (
e.g., acarbose, miglitol), insulins (including insulin secretagogues and insulin sensitizers),
meglitinides (
e.g., repaglinide), sulfonylureas (
e.g., glimepiride, glyburide, gliclazide, chlorpropamide, and glipizide), biguanide/glyburide
combinations (
e.g., Glucovance), thiazolidinediones (
e.g., troglitazone, rosiglitazone, and pioglitazone), PPAR-alpha agonists, PPAR-gamma
agonists, PPAR alpha/gamma dual agonists, glycogen phosphorylase inhibitors, inhibitors
of fatty acid binding protein (aP2), glucagon-like peptide-1 (GLP-1) or other agonists
of the GLP-1 receptor, dipeptidyl peptidase IV (DPP4) inhibitors, and sodium-glucose
co-transporter 2 (SGLT2) inhibitors (
e.g., dapagliflozin, canagliflozin, and LX-4211).
[0084] Pharmaceutical formulations may be adapted for administration by any appropriate
route, for example by the oral (including buccal or sublingual), rectal, nasal, topical
(including buccal, sublingual, or transdermal), vaginal, or parenteral (including
subcutaneous, intracutaneous, intramuscular, intra-articular, intrasynovial, intrasternal,
intrathecal, intralesional, intravenous, or intradermal injections or infusions) route.
Such formulations may be prepared by any method known in the art of pharmacy, for
example by bringing into association the active ingredient with the carrier(s) or
excipient(s). Oral administration or administration by injection are preferred.
[0085] Pharmaceutical formulations adapted for oral administration may be presented as discrete
units such as capsules or tablets; powders or granules; solutions or suspensions in
aqueous or non-aqueous liquids; edible foams or whips; or oil-in-water liquid emulsions
or water-in-oil emulsions.
[0086] For instance, for oral administration in the form of a tablet or capsule, the active
drug component can be combined with an oral, non-toxic pharmaceutically acceptable
inert carrier such as ethanol, glycerol, water, and the like. Powders are prepared
by comminuting the compound to a suitable fine size and mixing with a similarly comminuted
pharmaceutical carrier such as an edible carbohydrate, as, for example, starch or
mannitol. Flavoring, preservative, dispersing, and coloring agent can also be present.
[0087] Capsules are made by preparing a powder mixture, as described above, and filling
formed gelatin sheaths. Glidants and lubricants such as colloidal silica, talc, magnesium
stearate, calcium stearate, or solid polyethylene glycol can be added to the powder
mixture before the filling operation. A disintegrating or solubilizing agent such
as agar-agar, calcium carbonate, or sodium carbonate can also be added to improve
the availability of the medicament when the capsule is ingested.
[0088] Moreover, when desired or necessary, suitable binders, lubricants, disintegrating
agents, and coloring agents can also be incorporated into the mixture. Suitable binders
include starch, gelatin, natural sugars such as glucose or beta-lactose, corn sweeteners,
natural and synthetic gums such as acacia, tragacanth or sodium alginate, carboxymethylcellulose,
polyethylene glycol, and the like. Lubricants used in these dosage forms include sodium
oleate, sodium chloride, and the like. Disintegrators include, without limitation,
starch, methyl cellulose, agar, betonite, xanthan gum, and the like. Tablets are formulated,
for example, by preparing a powder mixture, granulating or slugging, adding a lubricant
and disintegrant, and pressing into tablets. A powder mixture is prepared by mixing
the compound, suitable comminuted, with a diluent or base as described above, and
optionally, with a binder such as carboxymethylcellulose, an aliginate, gelating,
or polyvinyl pyrrolidone, a solution retardant such as paraffin, a resorption accelerator
such as a quaternary salt and/or and absorption agent such as betonite, kaolin, or
dicalcium phosphate. The powder mixture can be granulated by wetting with a binder
such as syrup, starch paste, acadia mucilage, or solutions of cellulosic or polymeric
materials and forcing through a screen. As an alternative to granulating, the powder
mixture can be run through the tablet machine and the result is imperfectly formed
slugs broken into granules. The granules can be lubricated to prevent sticking to
the tablet forming dies by means of the addition of stearic acid, a stearate salt,
talc, or mineral oil. The lubricated mixture is then compressed into tablets. The
compounds of the present disclosure can also be combined with a free flowing inert
carrier and compressed into tablets directly without going through the granulating
or slugging steps. A clear or opaque protective coating consisting of a sealing coat
of shellac, a coating of sugar or polymeric material, and a polish coating of wax
can be provided. Dyestuffs can be added to these coatings to distinguish different
unit dosages.
[0089] Oral fluids such as solution, syrups, and elixirs can be prepared in dosage unit
form so that a given quantity contains a predetermined amount of the compound. Syrups
can be prepared by dissolving the compound in a suitably flavored aqueous solution,
while elixirs are prepared through the use of a non-toxic vehicle. Solubilizers and
emulsifiers such as ethoxylated isostearyl alcohols and polyoxyethylene sorbitol ethers,
preservatives, flavor additive such as peppermint oil or natural sweeteners, or saccharin
or other artificial sweeteners, and the like can also be added.
[0090] Where appropriate, dosage unit formulations for oral administration can be microencapsulated.
The formulation can also be prepared to prolong or sustain the release as for example
by coating or embedding particulate material in polymers, wax, or the like.
[0091] The compounds of formula (I), and pharmaceutically acceptable salts thereof, can
also be administered in the form of liposome delivery systems, such as small unilamellar
vesicles, large unilamellar vesicles, and multilamellar vesicles. Liposomes can be
formed from a variety of phopholipids, such as cholesterol, stearylamine, or phophatidylcholines.
[0092] The compounds of formula (I) and pharmaceutically acceptable salts thereof may also
be delivered by the use of monoclonal antibodies as individual carriers to which the
compound molecules are coupled. The compounds may also be coupled with soluble polymers
as targetable drug carriers. Such polymers can include polyvinylpyrrolidone, pyran
copolymer, polyhydroxypropylmethacrylamidephenol, polyhydroxyethylaspartamidephenol,
or polyethyleneoxidepolylysine substituted with palitoyl residues. Furthermore, the
compounds may be coupled to a class of biodegradable polymers useful in achieving
controlled release of a drug, for example, polylactic acid, polepsilon caprolactone,
polyhydroxy butyric acid, polyorthoesters, polyacetals, polydihydropyrans, polycyanoacrylates,
and cross-linked or amphipathic block copolymers of hydrogels.
[0093] Pharmaceutical formulations adapted for transdermal administration may be presented
as discrete patches intended to remain in intimate contact with the epidermis of the
recipient for a prolonged period of time. For example, the active ingredient may be
delivered from the patch by iontophoresis as generally described in
Pharmaceutical Research 1986, 3(6), 318.
[0094] Pharmaceutical formulations adapted for topical administration may be formulated
as ointments, creams, suspensions, lotions, powders, solutions, pastes, gels, sprays,
aerosols, or oils.
[0095] Pharmaceutical formulations adapted for rectal administration may be presented as
suppositories or as enemas.
[0096] Pharmaceutical formulations adapted for nasal administration wherein the carrier
is a solid include a course powder having a particle size for example in the range
20 to 500 microns which is administered in the manner in which snuff is taken,
i.e., by rapid inhalation through the nasal passage from a container of the powder held
close up to the nose. Suitable formulations wherein the carrier is a liquid, for administration
as a nasal spray or nasal drops, include aqueous or oil solutions of the active ingredient.
[0097] Pharmaceutical formulations adapted for administration by inhalation include fine
particle dusts or mists, which may be generated by means of various types of metered,
dose pressurized aerosols, nebulizers, or insufflators.
[0098] Pharmaceutical formulations adapted for vaginal administration may be presented as
pessaries, tampons, creams, gels, pastes, foams, or spray formulations.
[0099] Pharmaceutical formulations adapted for parenteral administration include aqueous
and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers,
bacteriostats, and soutes which render the formulation isotonic with the blood of
the intended recipient; and aqueous and non-aqueous sterile suspensions which may
include suspending agents and thickening agents. The formulations may be presented
in unit-dose or multi-dose containers, for example sealed ampoules and vials, and
may be stored in a freeze-dried (lyophilized) condition requiring only the addition
of the sterile liquid carrier, for example water for injections, immediately prior
to use. Extemporaneous injection solutions and suspensions may be prepared from sterile
powders, granules, and tablets.
[0100] It should be understood that in addition to the ingredients particularly mentioned
above, the formulations may include other agents conventional in the art having regard
to the type of formulation in question, for example those suitable for oral administration
may include flavoring agents.
[0101] The term "patient" includes both human and other mammals.
Unless otherwise indicated, the terms "manage," "managing", and "management" encompass
preventing the recurrence of the specified disease or disorder in a patient who has
already suffered from the disease or disorder, and/or lengthening the time that a
patient who has suffered from the disease or disorder remains in remission. The terms
encompass modulating the threshold, development and/or duration of the disease or
disorder, or changing the way that a patient responds to the disease or disorder.
[0102] The term "treating" refers to: (i) preventing a disease, disorder or condition from
occurring in a patient that may be predisposed to the disease, disorder, and/or condition
but has not yet been diagnosed as having it; (ii) inhibiting the disease, disorder,
or condition, i.e., arresting its development; and (iii) relieving the disease, disorder,
or condition, i.e., causing regression of the disease, disorder, and/or condition.
[0103] This disclosure is intended to encompass compounds having Formula (I) when prepared
by synthetic processes or by metabolic processes including those occurring in the
human or animal body
(in vivo) or processes occurring
in vitro.
[0104] The abbreviations used in the present application, including particularly in the
illustrative schemes and examples which follow, are well-known to those skilled in
the art. Some of the abbreviations used are as follows: RT or rt or r.t. for room
temperature or retention time (context will dictate);
tR for retention time; h or hr or hrs for hours; min or mins for minutes; MeOH for methanol;
EtOH for ethanol; EtOAc or EtOAC for ethyl acetate; OAc for acetate; DCM for dichloromethane;
DMA for
N,
N-dimethylacetamide; DMF for N,N-dimethylformamide; NMP for N-methylpyrrolidinone;
MeCN or ACN for acetonitrile; AcCl for acetyl chloride; THF for tetrahydrofuran; DMSO
for dimethylsulfoxide; MeOD for CD
3OD; m-CPBA for meta-chloroperoxybenzoic acid; DCM for dichloromethane; Me for methyl;
Et for ethyl; Ac for acetyl; Ph for phenyl; BOC or Boc for
tert-butoxycarbonyl; EDC for 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide; DBU for 1,8-diazabicycloundec-7-ene;
HOBT or HOBt for hydroxybenzotriazole; NCS for N-chlorosuccinimide; TEA or Et
3N for triethylamine; DIPEA, DIEA, or
i-Pr
2NEt for diisopropylethylamine; DEA for diethylamine; DAST for diethylaminosulfur trifluoride;
NBS for
N-bromosuccinimide; TOSMIC for tosylmethyl isocyanide; DIBAL for diisobutylaluminum
hydride; LDA for lithium diisopropylamide; TFA for trifluoroacetic acid; dppf or DPPF
for 1,1'-bis(diphenylphosphino)ferrocene; dba for dibenzylidiendiacetone; n-BuLi for
n-butyllithium; LHMDS or LiHMDS for lithium hexamethyldisilazide; TMS for trimethylsilyl;
and PMB-Cl for para-methoxybenzyl chloride.
EXAMPLES
[0105] The present disclosure will now be described in connection with certain embodiments
which are not intended to limit its scope. On the contrary, the present disclosure
covers all alternatives, modifications, and equivalents as can be included within
the scope of the claims. Thus, the following examples, which include specific embodiments,
will illustrate one practice of the present disclosure, it being understood that the
examples are for the purposes of illustration of certain embodiments and are presented
to provide what is believed to be the most useful and readily understood description
of its procedures and conceptual aspects.
[0106] The compounds of the present disclosure may be prepared using the reactions and techniques
described in this section as well as other synthetic methods known to those of ordinary
skill in the art. The reactions are performed in solvents appropriate to the reagents
and materials employed and suitable for the transformation being effected. Also, in
the description of the synthetic methods described below, it is to be understood that
all proposed reaction conditions, including choice of solvents, reaction temperature,
duration of the experiment and workup procedures, are chosen to be the conditions
standard for that reaction, which should be readily recognized by one skilled in the
art. It is understood by one skilled in the art of organic synthesis that the functionality
present on various portions of the molecule must be compatible with the reagents and
reactions proposed. Such restrictions to the substituents which are compatible with
the reaction conditions will be readily apparent to one skilled in the art and alternate
methods must then be used.

[0107] The compound of formula
9 is prepared by method outlined in Scheme 1. 4-Chloronicotinic acid can be subjected
to esterification using standard conditions such as treatment with oxalyl chloride
and methanol. The ester
2, so obtained can be subjected to Suzuki cross coupling reaction with an appropriate
coupling partner such as fluoroboronic acid
3, under standard Suzuki conditions employing a base such as cesium carbonate and a
catalyst such as Pd(PPh
3)
4 as described by
Zhang, Lei et. al. (journal of Medicinal Chemistry, 2011, 54, 1724 - 1739). The biaryl ester
4, can then be subjected to palladium catalyzed ether synthesis including reaction
conditions familiar to those skilled in the art following procedures such as those
described by
Gowrisankar, et. al. (J. Am. Chem. Soc. 2010, 132, 11592-11598). The reactions can be performed using appropriately protected, racemic or optically
amino alcohols to afford racemic or optically pure ethers. The biaryl ester represented
by formula
5, can be subjected to hydrolysis to yield corresponding carboxylic acid
6 under standard saponification conditions using a base such as lithium hydroxide in
a solvent such as water as described in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.). The acid
6 can be converted to amide
7 by using standard coupling conditions such as EDC, HOBt and ammonium chloride. The
amide 7, upon treatment with a hydride source such as sodium hydride in a solvent
such as THF under inert atmosphere can afford the constrained lactam,
8. The constrained lactam ether analog represented by
8 can be subjected to deprotection of the side chain amino group using appropriate
conditions as described in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to yield compounds represented by formula
9.

[0108] The compounds represented by formula
13 and
14 are prepared by methods outlined in Scheme 2. The biaryl ester
4, prepared as described in Scheme 1, can be subjected to hydrolysis under standard
saponification conditions using a base such as lithium or sodium hydroxide in a solvent
such as water as described in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to yield corresponding carboxylic acids, which upon treatment with standard amide
coupling conditions such as EDC, HOBt and ammonium chloride or substituted amine can
be converted to amides
10. Cyclization of amides
10 can be affected by treatment with a hydride source such as sodium hydride in a solvent
such as THF under inert atmosphere to afford constrained lactam chloro cores
11. Chloro cores
11 can be subjected to palladium catalyzed ether synthesis using reaction conditions
familiar to those skilled in the art following procedures such as those described
by
Gowrisankar, et. al. (J. Am. Chem. Soc. 2010, 132, 11592-11598) to afford compounds represented by formula
12. The reactions can be performed using appropriately protected, racemic or optically
pure (S) or (R)-aminoalcohols to afford racemic or optically pure ethers
12. The ether analogs can be subjected to deprotection of the side chain amino group
using appropriate conditions as described in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to yield compounds of formula
13. In cases where R
2 is serving as a protecting group, this group can be removed using appropriate conditions
as described in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.)

[0109] The compounds represented by formula
17 and
19 are prepared by methods outlined in Scheme 3. The constrained lactam ether,
15, synthesized as shown in Scheme 2, can be subjected to halogenation employing N-halosuccinimide
in polar aprotic solvents such as acetonitrile in the dark to yield mono-halo (X =
halo, R
3 = H) or dihalo-substituted (R
3 = X = halo) ethers
16. The side chain of ethers
16 can be subjected to deprotection using appropriate conditions as described in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to yield compounds of formula
17. Alternatively, compound
16 can be subjected to a palladium coupling such as Suzuki cross coupling reaction with
an appropriate coupling partner such as trimethylboroxine or cyclopropyl boronic acid
under standard Suzuki conditions employing a base such as cesium carbonate and a catalyst
such as Pd(PPh
3)
4 as described by
Zhang, Lei et. al. (journal of Medicinal Chemistry, 2011, 54, 1724 - 1739), or to a copper catalyzed cyanation reaction as described by
Miroslav et.al. (Collection of Czechoslovak Chemical Communications, 1983, 48, 1765-1773) to install R
4 of the compounds represented by formula
18. Lactam
16 can be subjected to a copper catalyzed hydroxylation reaction using conditions such
as those described by
Punniyamurthy et. al. (Synthesis, 2010, 4268 - 4272) to provide
18 wherein R
4 = OH. The ether analogs
18 can be subjected to deprotection of the side chain amino group using appropriate
conditions as described
in Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to yield compounds of formula
19.

[0110] The compounds represented by formula
29 can be prepared as shown in Scheme 4. Boc-protection of
20 using base such as LiHMDS and Boc anhydride led to
21. Directed
ortho-metallation followed by treatment with dimethylformamide can furnish the pyridine
aldehyde derivative
22 using methods such as those described by
Charles et. al. (J. Med. Chem., 2010, 53, 3330 - 3348). The aldehyde can then be subjected to Suzuki cross coupling reaction with an appropriate
coupling partner such as fluoroboronic acid
3, under standard Suzuki conditions employing a base such as cesium carbonate and a
catalyst such as Pd(PPh
3)
4 as described by
Zhang, Lei et. al. (journal of Medicinal Chemistry, 2011, 54, 1724 - 1739) to give biaryl aldehyde
23. Treatment of biaryl aldehyde
23 with methyl amine can provide cyclic iminium fluoride
24, which upon oxidation with reagents such as KinO4 give lactam
25. Treatment of lactam
25 with trifluoroacetic acid can afford
26, which can be protected with a group such as p-methoxy benzyl using appropriate conditions
as described in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) can afford lactam
27. Lactam core
27 can be subjected to palladium catalyzed ether synthesis using reaction conditions
familiar to those skilled in the art following procedures such as those described
by
Gowrisankar, et. al. (J. Am. Chem. Soc. 2010, 132, 11592-11598) to afford compound represented by formula
28. The ether analog can be subjected to global deprotection of the side chain amino
group using appropriate conditions as described in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to yield compound
29.

[0111] The compounds represented by the formula
39 can be prepared as shown in Scheme 5. Bromination of
30 with NBS followed by acylation with acetyl chloride and pyridine can furnish bromide
31. Suzuki cross coupling of the bromide
31 with vinyl boronic acid anhydride pyridine complex under standard Suzuki conditions
employing base such as sodium carbonate and a catalyst such as Pd(PPh
3)
4 as described by
Zhang, Lei et. al. (Journal of Medicinal Chemistry, 2011, 54, 1724 - 1739) can furnish vinyl pyridine
32. Vinyl pyridine 32 can be oxidized using osmium tetroxide and sodium metaperiodate
to yield corresponding aldehyde
33, which can then be subjected to Suzuki cross coupling reaction with an appropriate
coupling partner such as fluoroboronic acid
3, under standard Suzuki conditions employing a base such as cesium carbonate and a
catalyst such as Pd(PPh
3)
4 as described by
Zhang, Lei et. al. (Journal of Medicinal Chemistry, 2011, 54, 1724 - 1739) to give biaryl aldehyde
34. Treatment of biaryl aldehyde
34 with methyl amine can lead to the cyclic iminium fluoride
35 which can be reduced to the corresponding constrained piperidine
36 by using an agent such as sodium borohydride. Constrained piperidine
36 upon oxidation with KinO4 can give lactam
37. Lactam core
37 can be subjected to palladium catalyzed ether synthesis using reaction conditions
familiar to those skilled in the art following procedures such as those described
by
Gowrisankar, et. al. (J. Am. Chem. Soc. 2010, 132, 11592-11598) to afford compound represented by formula
38. The ether analog can be subjected to deprotection of the side chain amino group using
appropriate conditions as described in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to yield compounds
39.

[0112] The compounds represented by formula
42 - 46 are prepared by methods outlined in Scheme 6. The constrained lactam ether,
40, synthesized as shown in Scheme 2, can be subjected to halogenation by employing
N-halosuccinimide in polar aprotic solvents such as acetonitrile in the dark to yield
mono-halo (X = halo, R
3 = H) or dihalo-substituted (R
3 = X = halo) ethers
41. Compound
41 can be subjected to a palladium coupling such as a Suzuki cross coupling reaction
with an appropriate coupling partner such as trimethylboroxine, vinylboronic acid
or cyclopropylboronic acid under standard Suzuki conditions employing a base such
as cesium carbonate and a catalyst such as Pd(PPh
3)
4 as described by
Zhang, Lei et. al. (journal of Medicinal Chemistry, 2011, 54, 1724 - 1739), or to a copper catalyzed cyanation reaction as described by
Miroslav et.al. (Collection of Czechoslovak Chemical Communications, 1983, 48, 1765-1773) to install R
4 of the compounds represented by formula
42. Lactam
41 can alternatively be subjected to a copper catalyzed hydroxylation reaction using
conditions such as those described by
Punniyamurthy et. al. (Synthesis, 2010, 4268 - 4272) to provide
42 wherein R
4 = OH. In the cases of intermediates
42 where R
4 = vinyl, oxidative cleavage of the vinyl group with reagents such as osmium tetroxide
and sodium periodate can provide aldehydes
44. The aldehyde can be converted to the difluoromethyl analog
45 by treatment with Deoxo-Fluor®. If R
1 contains an amine group or another functional group that is protected, the protecting
group in analogs
42 and
45 is removed by treating the substrate with the appropriate reagents as described in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to yield compounds of formula
43 and
46, respectively.

[0113] The compounds represented by formula
47 and
48 are prepared by methods outlined in Scheme 7. The aldehyde,
44, synthesized as shown in Scheme 6, can be subjected to TOSMIC and a base such as potassium
carbonate to afford oxazoles
47. Alternatively, aldehydes
44 can be subjected to a reduction with reagents such as sodium borohydride or lithium
borohydride in a solvent such as EtOH or MeOH to yield compounds represented by formula
48. If R
1 contains an amine group or another functional group that is protected, the protecting
group is removed by treating the substrate with the appropriate reagents as described
in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to provide deprotected compounds of the formula
47 and
48.

[0114] The compounds represented by formula
52 - 53 are prepared by methods outlined in Scheme 8. The constrained lactam ether,
49, synthesized as shown in the above schemes, can be subjected to halogenation employing
N-halosuccinimide in polar aprotic solvents such as acetonitrile in the dark to yield
halo ethers
50. Compound
50 can be subjected to a palladium coupling such as Suzuki cross coupling reaction with
an appropriate coupling partner such as a vinylboronic acid under standard Suzuki
conditions employing a base such as cesium carbonate and a catalyst such as Pd(PPh
3)
4 as described by
Zhang, Lei et. al. (journal of Medicinal Chemistry, 2011, 54, 1724 - 1739), or to a Stille coupling with an appropriate coupling partner such as a tributyl(1-ethoxyvinyl)stannane
or under standard Stille conditions employing a catalyst such as tris(dibenzylidineacetone)dipalladium
and a ligand such as DPPF at elevated temperatures to afford compounds represented
by formula
51. The vinyl group of
51 can be subjected to a hydrogenation in the presence of palladium on carbon to provide
compounds represented by formula
52. Alternatively, of R is an alkoxy group,
51 can be subjected to hydrolysis with an aqueous acid such as HCl to provide ketone
compounds represented by formula
53. If R
1 contains an amine group or another functional group that is protected, the protecting
group is removed by treating the substrate with the appropriate reagents as described
in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to provide deprotected compounds of the formula
52 and
53.

[0115] The compounds represented by formula
54 are prepared by methods outlined in Scheme 9. The constrained lactam ether,
53, synthesized as shown in Scheme 8, can be treated with a Grignard reagent in a solvent
such as diethyl ether or THF to provide compounds represented by formula
54. If R
1 contains an amine group or another functional group that is protected, the protecting
group is removed by treating the substrate with the appropriate reagents as described
in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to provide deprotected compounds of the formula
54.

[0116] The compounds represented by formula
56 - 58 are prepared by methods outlined in Scheme 10. The constrained lactam ether,
50, synthesized as shown in Scheme 8, can be subjected to cyanation employing a standard
Negishi coupling using Zn(CN)
2 and a catalyst such as Pd(PPh
3)
4 in solvent such as DMF, or using CuCN at temperatures ranging from 50 to 120 °C to
yield compounds represented by formula
55. Nitrile compound
55 can be hydrolyzed with aqueous HCl at elevated temperatures followed by ester formation
with thionyl or oxalyl chloride followed by quenching with an alcohol to afford compounds
represented by formula
57. Alternatively, nitrile compound
55 can be hydrolyzed to the amide by employing a base such as cesium carbonate in a
solvent such as DMF at temperatures ranging from 100 -120 °C to provide compounds
represented by formula
58. If R
1 contains an amine group or another functional group that is protected, the protecting
group is removed by treating the substrate with the appropriate reagents as described
in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to provide compounds of formula
56 - 58.

[0117] The compounds represented by formula
60 - 62 are prepared by methods outlined in Scheme 11. The constrained lactam ether,
50, synthesized as shown in Scheme 8, can be subjected to copper catalyzed trifluoromethylation
by employing copper(I) iodide and trimethyl(trifluoromethyl)silane in a solvent such
as NMP at high temperatures to afford compounds represented by formula
59. Alternatively, halo compound
50 can be subjected to copper-catalyzed coupling employing copper(I) iodide, 1
H-pyrazole,
N1,
N2-dimethylethane-1,2-diamine, and a base such as potassium phosphate in a solvent
such as DMF and 1,4-dioxane at high temperatures to afford compounds represented by
formula
60. Alternatively, halo compound
50 can be subjected to copper catalyzed methoxylation employing copper(I) iodide, L-proline,
sodium methoxide, and a base such as potassium carbonate in a solvent such as DMSO
at elevated temperatures to afford compounds represented by formula
61. Alternatively, halo compound
50 can be subjected to copper catalyzed sulfoxylation employing copper(I) iodide, L-proline,
methanesulfinic acid sodium salt, and a base such as sodium hydroxide in a solvent
such as DMSO at elevated temperatures to afford compounds represented by formula
62. If R
1 contains an amine group or another functional group that is protected, the protecting
group is removed by treating the substrate with the appropriate reagents as described
in
Protective Groups in Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley &
Sons, Inc.) to provide compounds of formula
60 - 62.

[0118] Intermediates represented by formula
65 are prepared by methods outlined in Scheme 12. The biaryl amide
11, prepared as described in Scheme 2, can be subjected to oxidation with
m-CPBA in a solvent such as DCM to afford compounds represented by formula
63. Intermediates
63 can be treated with POCl
3 followed by sodium methoxide in methanol to afford intermediates represented by formula
65.

[0119] The intermediates represented by formula
67 are prepared by methods outlined in Scheme 13. The biaryl amides
11, prepared as described in Scheme 2, can be subjected to oxidation with selenium dioxide
in a solvent such as AcOH to afford compounds represented by formula
66. Intermediates
66 can be treated with bis-(2-methoxyethyl)aminosulfur trifluoride in a solvent such
as DCM to afford intermediates represented by formula
67.

[0120] The intermediates represented by formula
68 are prepared by methods outlined in Scheme 14. Biaryl amides
8, prepared as described in Scheme 1, can be subjected to alkylation with an alkyl halide
in the presence of a base such as NaH or potassium carbonate in a solvent such as
DMF, or in the case of R
1 = CH
2CH
2OH, the amide can be subjected to ethyl carbonate in the presence of 18-crown-6 and
a base such as potassium carbonate to afford intermediates represented by formula
68.

[0121] The intermediates represented by formula
71 and
72 are prepared by methods outlined in Scheme 15. The biaryl amide
11, prepared as described in Scheme 2, can be subjected to halogenation by employing
N-halosuccinimide in polar aprotic solvents such as acetonitrile in the dark to yield
halides
69. Compounds
69 can be treated with copper (I) iodide and potassium hydroxide in the presence of
1,10-phenanthroline to afforded intermediates represented by the formula
70. Intermediates
70 can be treated with sodium 2-chloro-2,2-difluoroacetate and a base such as potassium
carbonate to afford intermediated represented by the formula
71. Alternatively, compounds
70 can be treated with a base such as sodium hydride and an alkylating agent such as
methyl iodide in a solvent such as DMF to afforded intermediates represented by the
formula
72.

[0122] The compounds represented by formula
74 and
75 are prepared by methods outlined in Scheme 16. The intermediate
73, prepared as described in Scheme 2, can be subjected to alkylation with methyl iodide
and a base such as sodium hydride in a solvent such as DMF, followed by deprotection
with TFA or HCl to afford compounds of the formula
74. Alternatively, intermediate
73 can be deprotected with TFA or HCl, followed by treatment with formaldehyde in formic
acid to afford compounds of the formula
75.

[0123] Intermediate
80 is prepared by methods outlined in Scheme 17. Intermediate
80 can be esterified by treatment with TMS-diazomethane in a solvent such as THF at
low temperature, or by converting the acid to the acid chloride with thionyl chloride
or oxalyl chloride and quenching with an alcohol such as MeOH or EtOH to provide ester
77.
[0124] Intermediate
77 can be subjected to osmium tetroxide and sodium periodate in the presence of 2,6-lutidine
in a solvent such as 1,4-dioxane and water to afford intermediate
78. Intermediate
78 can be treated with DAST to provide intermediate
79. Intermediate
79 can be subjected to reduction with a reagent such as lithium aluminum hydride or
lithium borohydride in a solvent such as THF to provide intermediate
80.

Intermediate
83 is prepared by methods outlined in Scheme 18. Intermediate
81 can be esterified by treatment with HCl in EtOH to provide ester
82. Intermediate
82 can be subjected to reduction with a reagent such as lithium aluminum hydride or
sodium borohydride in a solvent such as THF to provide intermediate
83.

[0125] Intermediate
90 is prepared by methods outlined in Scheme 19. Intermediate
84 can be esterified by treatment with TMSCl in MeOH to provide ester
85. Intermediate
85 can be treated with Boc
2O and DMAP in a solvent such as acetonitrile to afford intermediate
86. Intermediate
86 can be subjected to reduction with a reagent such as DIBAL in a solvent such as THF
or diethyl ether to provide intermediate
87. Intermediate
87 can be mono-deprotected by treatment with LiBr in acetonitrile to afford intermediate
88. Intermediate
88 can be subjected to sodium 2-chloro-2,2-difluoroacetate in DMF to afford intermediate
89. Intermediate
89 can be reduced with LiBH
4 in THF to afford intermediate
90.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0127] In the following examples, proton NMR spectra were recorded on either a Bruker 400
or 500 MHz NMR spectrometer. Chemical shifts are reported in δ values relative to
tetramethylsilane. LC/MS were run on a Shimadzu LC coupled to a Waters Micromass ZQ.
HPLC retention times were obtained using at least one of the following methods:
LC-MS methods:
[0128]
LC/MS Method A: Column : PUROSPHER@star RP-18 (4X55mm), 3µm; Buffer : 20mM NH4OAC IN WATER; Mphase A : Buffer + ACN(90+10); Mphase B : Buffer + MeCN(10+90); Flow
: 2.5 mL/min)
LC/MS Method B: Column : ZORBAX SB C18 (46X50mm), 5µm; Positive mode Mphase A : 10%
MeOH - 90% H2O - 0.1% TFA; Mphase B : 90% MeOH - 10% H2O - 0.1% TFA; Flow : 5 mL/min)
LC/MS Method C: Column - Ascentis Express C8 (5X2.1mm), 2.7µm; Mphase A : 2%MeCN -
98%H2O - 10mM NH4COOH; Mphase B : 98%ACN - 2%H2O - 10 mM NH4COOH; Flow : 1 mL/min)
LC/MS Method D: Column-ACQUITY UPLC BEH C18 (2.1 X 50 mm), 1.7µm; Mphase A :0.1% TFA
in water; Mphase B : 1% TFA in ACN; Flow : 1/min)
LC/MS Method E: Column -ACQUITY UPLC BEH C18 (2.1 X 50 mm), 1.7µm; Mphase A : 5 mM
NH4OAc:AC (95:5); Mphase B : 5 mM NH4OAc: ACN (5:95); Flow: 1/min)
LC/MS Method F: Column : X-Bridge BEH C18 (50 X 2.1 mm), 2.5µm; Mphase A : ACN + H2O (2+98) + 0.1% TFA; Mphase B : ACN + H2O (98+2) + 0.05% TFA; Flow: 1.2 mL/min.
LC-MS method G: Column : Kinetex C18 (50 X 2.1 mm), 2.6um: Mphase A: 2%ACN - 98%H2O - 10mM; Mphase B : 98%ACN - 2%H2O - 10mM NH4COOH; Flow: 1/min).
LC-MS method H: Column : BEH C18 (50 X 3.0 mm), 1.7 µm: Mphase A: 5%ACN - 95%H2O - 10mM; Mphase B : 95%ACN - 5%H2O - 10mM NH4COOH; Flow : 1.2/min).
LC-MS method I: Column : Ace Excel 2 C18 (50 X 3.0 mm), 2.0 µm: Mphase A: 2%ACN -
98%Hz, - 10mM; Mphase B : 98%ACN - 2%H2O - 10mM NH4COOH; Flow: 1.2/min).
Chiral HPLC methods:
[0129]
Method A: CHIRALCEL OJH (250x4.6) mm 5 micron Mob. phase: 0.2% DEA in n-hexane : ethanol
(80:20)
Method B: CHIRALPAK AD-H (250x4.6) mm 5 micron Mob. Phase A: 0.2% DEA in n-hexane
(70) B: ethanol (30)
Method C: CHIRALPAK- ASH (250x4.6) mm 5 micron Mob. Phase A: 0.2% DEA in n-hexane
: ethanol (90:10)
Analytical HPLC methods:
[0130]
Method A: Waters analytical C18 sunfire column (4.6 x 150 mm, 3.5 µm); mobile phase:
Buffer: 0.05% TFA in H2O pH = 2.5 adjusted with ammonia A = buffer and acetonitrile (95:5), B = acetonitrile
and buffer (95:5); 0 - 15 min, 0% B → 50% B; 15 - 18 min, 50% B → 100% B; 18 - 23
min, 100% B; flow rate = 1 mL/min; λ = 254 nm and 220 nm; run time = 28 min.
Method B: Waters analytical phenyl xbridge column (4.6 x 150 mm, 3.5 µm), mobile phase:
Buffer: 0.05% TFA in H2O pH = 2.5 adjusted with ammonia A = buffer and acetonitrile (95:5), B = acetonitrile
and buffer (95:5); 0 - 15 min, 0% B → 50% B; 15 - 18 min, 50% B → 100% B; 18 - 23
min, 100% B; flow rate = 1 mL/min; λ = 254 nm and 220 nm; run time = 28 min.
Method C: Waters analytical C18 sunfire column (3.0 x 150 mm, 3.5 µm); mobile phase:
A = 10mM amm. bicarbonate (pH=9.5)/95% H2O/5% methanol, B = 10mM amm. bicarbonate
(pH=9.5)/5% H2O/95% methanol; 0 - 15 min, 0% B → 100% B; 15 - 18 min, 100% B; flow rate = 1 mL/min;
λ = 254 nm; run time = 18 min.
Method D: Waters analytical phenyl xbridge column (3.0 x 150 mm, 3.5 µm), mobile phase:
A = 10mM amm. bicarbonate (pH=9.5)/95% H2O/5% methanol, B = 10mM amm. bicarbonate
(pH=9.5)/5% H2O/95% methanol; 0 - 15 min, 0% B → 100% B; 15 - 18 min, 100% B; flow
rate = 1 mL/min; λ = 254 nm; run time = 18 min.
Example 1
(S)-8-(2-amino-4-methylpentyloxy)benzo[c][2,7]naphthyridin-5(6H)-one
[0131]

Part A. Methyl 4-chloronicotinate
[0132] A solution of 4-chloronicotinic acid (20 g, 127 mmol) in dichloromethane (600 mL)
and DMF (15 mL), cooled to 0 °C, was treated with oxalyl chloride (27.8 mL, 317 mmol)
dropwise. After addition, the mixture was stirred for another 2 h at RT. The mixture
was then cooled back to 0 °C and MeOH (30 mL) was added slowly. The reaction was warmed
to RT and stirred for 0.5 h. The mixture was diluted with dichloromethane (500 mL)
and saturated aqueous NaHCO
3 (100 mL) then extracted with DCM (3x1000 mL). The DCM layer was washed with brine
(2x100 mL), dried over sodium sulfate and concentrated under reduced pressure. The
crude product obtained as yellow oil (20 g, 92 % yield) was taken to the next step
without further purification. LC/MS (ESI)
m/
e 172.0 [(M+H)
+, calcd for C
7H
7ClNO
2: 172.6]; LC/MS retention time (method B):
tR = 1.21 min.
1H NMR (400 MHz,
CDCl3) δ ppm 9.27 (s, 1H), 8.86 (bs, 1H), 7.98 (bs, 1H), 4.05 (s, 3H).

Part B. Methyl 4-(4-chloro-2-fluorophenyl)nicotinate
[0133] Methyl 4-chloronicotinate (20 g, 117 mmol), (4-chloro-2-fluorophenyl)boronic acid
(22.4 g, 128 mmol), Pd(Ph
3P)
4 (9.4 g, 8.16 mmol) and Cs
2CO
3 (114 g, 350 mmol) were taken in a solvent mixture of 1,4-dioxane (400 mL) and water
(30 mL) and purged with nitrogen for 5 min and heated to 85°C. After overnight stirring
at this temperature the reaction mixture was diluted with ethyl acetate and filtered
through a bed of diatomaceous earth (Celite
®). The bed was further washed with ethyl acetate. Combined filtrate was washed with
water (1x100 mL), dried (Na
2SO
4) and concentrated under reduced pressure to afford the crude product which was purified
via combi flash (gradient of methanol and chloroform) to afford methyl 4-(4-chloro-2-fluorophenyl)nicotinate
(13 g, 48.9 mmol, 42%, with purity of 77% by LC/MS) as a brown solid. LC/MS (ESI)
m/
e 266.0 [(M+H)
+, calcd for C
13H
10ClFNO
2 266.1]; LC/MS retention time (method B):
tR = 1.69 min.

Part C. (S)-methyl 4-(4-((2-((tert-butoxycarbonyl)amino)-4-methylpentyl)oxy)-2-fluorophenyl)nicotinate
[0134] Methyl 4-(4-chloro-2-fluorophenyl)nicotinate (50 mg, 0.188 mmol) in toluene (1 mL)
was treated with cesium carbonate (92 mg, 0.282 mmol) and
N-Boc-L-Leucinol (121 mg, 0.565 mmol). The mixture was purged with nitrogen gas for
5 min and treated with di-
tert-butyl(2',4',6'-triisopropyl-[1,1'-biphenyl]-2-yl)phosphine (48.0 mg, 0.113 mmol).
After purging the mixture with nitrogen for another 5 min, palladium(II)acetate (42.3
mg, 0.188 mmol) was added and nitrogen bubbled through for another 10 min. The mixture
was sealed tightly and heated at 80 °C for 12 h. The mixture was filtered through
a bed of diatomaceous earth (Celite
®) and washed with ethyl acetate (2x3 mL). The washings were concentrated under reduced
pressure. The residue was purified by combi flash (ethyl acetate and petroleum ether)
to afford (
S)-methyl 4-(4-((2-((
tert-butoxycarbonyl)amino)-4-methylpentyl)oxy)-2-fluorophenyl)nicotinate (50 mg, 0.112
mmol, 60% yield). LC/MS (ESI)
m/
e 447.2 [(M+H)
+, calcd for C
24H
32FN
2O
5 447.2]; LC/MS retention time (method C):
tR = 2.17 min.

Part D. (S)-4-(4-((2-((tert-butoxycarbonyl)amino)-4-methylpentyl)oxy)-2-fluorophenyl)nicotinic acid
[0135] (
S)-methyl-4-(4-((2-((
tert-butoxycarbonyl)amino)-4-methylpentyl)oxy)-2 fluorophenyl)nicotinate (50.0 mg, 0.112
mmol) was taken in a mixture of tetrahydrofuran (1 mL), methanol (1 mL) and water
(1 mL). To the solution was added lithium hydroxide (8.05 mg, 0.336 mmol) and the
reaction mixture was stirred at RT for 2 h. The reaction mixture was concentrated
under reduced pressure and the residue was diluted with water and the pH adjusted
to 4 using 1.5N aqueous HCl. The crude product from the aqueous layer was extracted
with ethyl acetate (3x5 mL). The combined organic layers were washed with brine (1x5
mL), dried (Na
2SO
4) and concentrated under reduced pressure to afford (
S)-4-(4-((2-((
tert-butoxycarbonyl)amino)-4-methylpentyl)oxy)-2-fluorophenyl)nicotinic acid (30 mg, 0.060
mmol, 53% yield) as an off-white solid. LC/MS (ESI)
m/
e 433.2 [(M+H)
+, calcd for C
23H
30FN
2O
5 433.2]; LC/MS retention time (method C):
tR = 1.74 min.

Part E. (S)-tert-butyl (1-(4-(3-carbamoylpyridin-4-yl)-3-fluorophenoxy)-4-methylpentan-2-yl)carbamate
[0136] (
S)-4-(4-((2-((
tert-butoxycarbonyl)amino)-4-methylpentyl)oxy)-2-fluorophenyl)nicotinic acid (75 mg, 0.173
mmol) was taken in DMF (2 mL) and cooled to 0 °C. To the solution was added EDC (49.9
mg, 0.260 mmol) and HOBT (53.1 mg, 0.347 mmol). After stirring the reaction mixture
for 5 min, ammonium chloride (55.7 mg, 1.040 mmol) was added and the resultant mixture
was stirred for 5 min. Diisopropylethylamine (0.121 mL, 0.694 mmol) was added and
the mixture was allowed to stir at room temperature for an additional 12 h. The mixture
was then quenched with ice and the residue was filtered and dried under vacuum to
afford (
S)-
tert-butyl (1-(4-(3-carbamoylpyridin-4-yl)-3-fluorophenoxy)-4-methylpentan-2-yl)carbamate
(50 mg, 0.098 mmol, 57% yield) as a light yellow solid. LC/MS (ESI)
m/
e 432.2 [(M+H)
+, calcd for C
23H
31FN
3O
4 432.2]; LC/MS retention time (method C):
tR = 1.83 min.

Part F. (S)-tert-butyl (4-methyl-1-((5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0137] Sodium hydride (5.56 mg, 0.232 mmol, 60% in mineral oil) was taken in tetrahydrofuran
(1 mL) and cooled to 0 °C. The suspension was treated with (
S)-
tert-butyl (1-(4-(3-carbamoylpyridin-4-yl)-3-fluorophenoxy)-4-methylpentan-2-yl)carbamate
(50 mg, 0.116 mmol) in THF (1 mL) dropwise and the temperature was maintained at 0
°C for 30 min. The reaction mixture was then allowed to warm to room temperature and
stirred for 2 h. The reaction was quenched with ice and extracted with ethyl acetate
(3x5 mL). The combined organic layers were washed with brine (1x5 mL), dried (Na
2SO
4) and concentrated under reduced pressure to afford (
S)-
tert-butyl (4-methyl-1-((5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (40 mg, 0.097 mmol, 84% yield) as
a colorless solid. LC/MS (ESI)
m/
e 412.2 [(M+H)
+, calcd for C
23H
30N
3O
4 412.2]; LC/MS retention time (method C):
tR = 1.97 min.

Part G. (S)-8-(2-amino-4-methylpentyloxy)benzo[c][2,7]naphthyridin-5(6H)-one
[0138] (
S)-
tert-butyl (4-methyl-1-((5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (10 mg, 0.024 mmol) in dichloromethane
(1 mL) was cooled to 0 °C. To the solution was added hydrogen chloride (0.886 mg,
0.012 mL, 0.024 mmol, 2M in diethyl ether) dropwise. The temperature of the reaction
mixture was maintained at 0 °C for 30 min and then the reaction mixture was allowed
to warm to room temperature and stirred for 2 h. The reaction mixture was then concentrated
under reduced pressure to afford (
S)-8-((2-amino-4-methylpentyl)oxy)benzo[
c][2,7]naphthyridin-5(6
H)-one (4 mg, 0.012 mmol, 49% yield) as a pale yellow solid. LC/MS (ESI)
m/
e 312.2 [(M+H)
+, calcd for C
18H
22N
3O
2 312.2]; LC/MS retention time (method A):
tR = 1.1 min; HPLC retention time (method A):
tR = 6.85 min; HPLC retention time (method B):
tR = 7.51 min
1H NMR (400 MHz,
D2O) δ ppm 9.30 (br. s., 1H), 8.77 (br. s., 1H), 8.36 (br. s., 1H), 8.07 (br. s., 1H),
6.95 (br. s., 1H), 6.72 (br. s., 1H), 4.41 (d,
J= 9.03 Hz, 1H), 4.26 (br. s., 1H), 3.89 (br. s., 1H), 3.38 (s, 1H), 1.72 - 1.88 (m,
2H), 1.05 (d,
J= 2.51 Hz, 6H).
Example 2
(S)-8-((2-amino-4-methylpentyl)oxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0139]

Part A. 4-(4-chloro-2-fluorophenyl)nicotinic acid
[0140] To a solution of methyl 4-(4-chloro-2-fluorophenyl)nicotinate (15 g, 56.5 mmol) (as
prepared in Ex 1, Part B) in a solvent mixture of methanol (150 mL) and water (150
mL) cooled to 0° C was added sodium hydroxide (9.03 g, 226 mmol) and the mixture was
warmed to room temperature and stirred for 1 h. The reaction mixture was concentrated
under reduced pressure and pH of the resultant aqueous solution was adjusted to pH
= 4 using 1.5 N Hydrochloric acid during which time the product crashed out as a solid.
Filtration of the mixture provided 4-(4-chloro-2-fluorophenyl)nicotinic acid (9 g,
35.8 mmol, 63% yield) as an off white solid. LC/MS (ESI)
m/
e 252.0 [(M+H)
+, calcd for C
12H
8ClFNO
2 252.1]; LC/MS retention time (method A):
tR = 0.97 min.

Part B. 4-(4-chloro-2-fluorophenyl)-N-methylnicotinamide
[0141] To a solution of 4-(4-chloro-2-fluorophenyl)nicotinic acid (2 g, 7.95 mmol in dichloromethane
(40 mL) cooled to 0 °C was added oxalyl chloride (2.09 mL, 23.8 mmol) followed by
DMF (2 mL). The reaction mixture was allowed to warm to room temperature and stirred
for 2 h. The reaction mixture was concentrated under reduced pressure and treated
with dichloromethane (25 mL). This solution was added to a mixture of methylamine
hydrochloride (5.37 g, 79 mmol) and triethylamine (11.08 mL, 79 mmol) in dichloromethane
(25 mL) cooled to 0 °C. The resultant mixture was stirred at room temperature for
3 h and then washed with a saturated solution of sodium bicarbonate. The organic layer
was separated, dried (Na
2SO
4) and concentrated under reduced pressure to afford 4-(4-chloro-2-fluorophenyl)-
N-methylnicotinamide (1.3 g, 4.91 mmol, 62%) as an off-white solid. LC/MS (ESI)
m/
e 265.1 [(M+H)
+, calcd for C
13H
11ClFN
2O 265.1]; LC/MS retention time (method C):
tR = 1.69 min.

Part C. 8-chloro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0142] Sodium hydride (80 mg, 3.32 mmol) was taken in THF (1 mL) and cooled to 0 °C. To
the suspension, 4-(4-chloro-2-fluorophenyl)-
N-methylnicotinamide (440 mg, 1.66 mmol) in THF (1 mL) was added dropwise and the temperature
was maintained at 0 °C for 30 min. The reaction mixture was then warmed to room temperature
and stirred for 2 h. The reaction mixture was quenched with ice and extracted with
ethyl acetate (3 x 5 mL). The combined organic layers were washed with brine (1 x
5 mL) dried (Na
2SO
4) and concentrated under reduced pressure to afford 8-chloro-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (440 mg, 1.798 mmol) as a light brown oil. LC/MS (ESI)
m/
e 245.1 [(M+H)
+, calcd for C
13H
10ClN
2O 245.1]; LC/MS retention time (method C):
tR = 1.79 min.

Part D. (S)-tert-butyl (4-methyl-1-((6-methyl-5-oxo-5,6 dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0143] To a solution of 8-chloro-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (440 mg, 1.80 mmol) in toluene (8 mL) at room temperature, was added cesium
carbonate (879 mg, 2.70 mmol) and di-
tert-butyl(2',4',6'-triisopropyl-[1,1'-biphenyl]-2-yl)phosphine (458 mg, 1.079 mmol) and
the mixture was degassed for 5 min. The mixture was then treated with
N-Boc L-Leucinol (1160 mg, 5.39 mmol) followed by palladium(II)acetate (121 mg, 0.54
mmol) and the mixture degassed for another 10 min. The reaction mixture was sealed
and heated at 80 °C. After overnight stirring the reaction mixture was cooled to room
temperature and filtered through diatomaceous earth (Celite
®). The bed was washed with ethyl acetate and the combined filtrate was concentrated
under reduced pressure to afford the crude product which was purified by combi flash
(gradient of ethyl acetate and petroleum ether) to afford (
S)-
tert-butyl (4-methyl-l-((6-methyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (190 mg, 0.34 mmol, 19% yield) as
an off-white solid. LC/MS (ESI)
m/
e 426.2 [(M+H)
+, calcd for C
24H
32N
3O
4 426.2]; LC/MS retention time (method C):
tR = 2.10 min.

Part E. (S)-8-((2-amino-4-methylpentyl)oxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0144] To a solution of (
S)-
tert-butyl (4-methyl-1-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (190mg, 0.447 mmol) in dichloromethane
(4 mL) at 0 °C was added hydrogen chloride (81 mg, 0.558 mL, 2.233 mmol) in 1,4-dioxane
(4 M) dropwise and the reaction mixture was stirred at 0 °C for 30 min then warmed
to room temperature and allowed to stir for 2 h. The solvents were removed under reduced
pressure to afford crude product which was purified by preparative HPLC (0.1% TFA
in water) to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (51 mg, 0.157 mmol, 35% yield) as a yellow solid. LC/MS (ESI)
m/
e 326.2 [(M+H)
+, calcd for C
19H
24N
3O
2 326.2]; LC/MS retention time (method A):
tR = 1.21 min; HPLC retention time (method A):
tR = 7.39 min; HPLC retention time (method B):
tR = 7.40 min.
1H NMR (400 MHz,
CD3OD) δ ppm 9.48 (s, 1H), 8.77 (d,
J= 5.77 Hz, 1H), 8.43 (d,
J= 8.78 Hz, 1H), 8.26 (d,
J= 5.77 Hz, 1H), 7.09 - 7.16 (m, 2H), 4.20 (dd,
J = 9.41, 3.89 Hz, 1H), 4.02 (dd,
J= 9.29, 7.03 Hz, 1H), 3.81 (s, 3H), 3.35 - 3.39 (m, 1H), 1.81 - 1.91 (m, 1H), 1.41
- 1.56 (m, 2H), 0.98 - 1.05 (m, 6H).
Example 3
(S)-8-(2-amino-4-methylpentyloxy)-9-bromo-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0145]

[0146] Part A. (
S)-
tert-butyl (1-((9-bromo-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
To a solution of (
S)-
tert-butyl (4-methyl-l-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (0.100 g, 0.235 mmol) (as prepared
in Ex. 2, Part D) in anhydrous acetonitrile (5 mL) was added
N-bromosuccinimide (0.042 g, 0.235 mmol) and the mixture was heated at 85 °C for 5 h.
The reaction mixture was diluted with water (10 mL), extracted with ethyl acetate
(2x20 mL). The combined organic layers were dried over sodium sulfate and evaporated
under reduced pressure to afford crude product which was purified by preparative TLC
(gradient of ethyl acetate and petroleum ether) to afford (
S)-
tert-butyl (1-((9-bromo-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (80 mg, 0.159 mmol, 68%
yield) as an off-white solid. LC/MS (ESI)
m/
e 504.2 [(M+H)
+, calcd for C
24H
31BrN
3O
4 504.1]; LC/MS retention time (method A):
tR = 2.23 min.

Part B. (S)-8-((2-amino-4-methylpentyl)oxy)-9-bromo-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0147] To a solution of (
S)-
tert-butyl (1-((9-bromo-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (80 mg, 1.586 mmol) in
anhydrous methanol (5 mL) was added a 4 M solution of HCl in 1,4-dioxane (2 mL, 8
mmol) dropwise at 0° C. The reaction mixture was warmed to room temperature and stirred
for 2 h. The mixture was then was concentrated under reduced pressure to afford crude
product which was purified by preparative HPLC (10 mM ammonium acetate in water ;
acetonitrile) to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-9-bromo-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (20 mg, 0.049 mmol, 30% yield) as an off-white solid. LC/MS (ESI)
m/
e 404.1 [(M+H)
+, calcd for C
19H
23BrN
3O
2 404.1]; LC/MS retention time (method A):
tR = 1.47 min; HPLC retention time (method A):
tR = 9.55 min; HPLC retention time (method B):
tR = 10.23 min;
1H NMR (400 MHz,
CD3OD) δ ppm 9.48 (s, 1H), 8.80 (d,
J = 5.77 Hz, 1H), 8.67 (s, 1 H), 8.26 (d,
J= 5.77 Hz, 1H), 7.15 (s, 1H), 4.37 (dd,
J= 9.54, 3.76 Hz, 1H), 4.18 (dd,
J = 9.66, 6.40 Hz, 1H), 3.83 (s, 3H), 3.48 - 3.56 (m, 1H), 1.89 (m, 1H), 1.51 - 1.72
(m, 2H), 1.05 (t,
J = 6.27 Hz, 6H).
Example 4
(S)-8-((2-amino-4-methylpentyl)oxy)-6,9-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0148]

Part A. (S)-tert-butyl (1-((6,9-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0149] In a 10 mL round-bottomed flask, (
S)-
tert-butyl (1-((9-bromo-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (as prepared in Ex. 3,
Part A) (150 mg, 0.297 mmol), 2,4,6-trimethyl-1,3,5,2,4,6-trioxatriborinane (41.1
mg, 0.327 mmol), Cs
2CO
3 (291 mg, 0.892 mmol) and PdCl
2(dppf) (21.76 mg, 0.030 mmol) were taken up in a mixture of 1,4-dioxane (2 mL) and
water (0.1 mL). The reaction mixture was purged with nitrogen for 5 min and heated
at 90° C for 15 h. 1,4-dioxane was removed under reduced pressure and the residue
was dissolved in ethyl acetate (20 mL). The ethyl acetate layer was washed with water
(10x2 mL) and dried over sodium sulfate. Removal of the solvent gave crude product
(0.08 g), which was filtered through silica-gel column (24 g silica-gel, MeOH-CHCl
3 mixture). The product was isolated as off-white solid (0.05 g, 0.11 mmol, 38% yield).
LC/MS (ES-API)
m/
e 440.2 [(M+H)
+, calcd for C
25H
34N
3O
4, 440.3]; LC/MS retention time (method B):
tR = 1.95 min.

Part B. (S)-8-((2-amino-4-methylpentyl)oxy)-6,9-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0150] In a 25 mL round-bottomed flask, (
S)-
tert-butyl (1-((6,9-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (80 mg, 0.182 mmol) was
taken in MeOH (6 mL). The reaction mixture was cooled to 0 °C and a 4M solution of
HCl in 1,4-dioxane (3.75 mL, 12 mmol) was added and the mixture stirred at RT for
2 h. The MeOH was removed and the crude product was dissolved in ethyl acetate (20
mL). The ethyl acetate layer was washed with water (10 mL) and dried over sodium sulfate.
Removal of the solvent gave crude product which was purified by silica-gel column
(MeOH-CHCl
3 mixture) to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-6,9-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (0.03 g, 0.09 mmol, 49% yield) as yellow solid. LC/MS (ESI)
m/
e 340.2 [(M+H)
+, calcd for C
20H
26N
3O
2, 340.4]; LC/MS retention time (method B):
tR = 1.33 min. HPLC retention time (method A):
tR = 8.58 min; HPLC retention time (method B):
tR = 8.12 min.
1H NMR (400 MHz,
CD3OD) δ ppm 9.51 (s, 1H), 8.79 (d,
J = 6.02 Hz, 1H), 8.40 (d,
J = 5.77 Hz, 1H), 8.33 (s, 1H), 7.10 (s, 1H), 4.50 (dd,
J = 10.67, 3.14 Hz, 1H), 4.36 (dd,
J = 10.67, 5.90 Hz, 1H), 3.77-3.87 (m, 4H), 2.46 (s, 3H), 1.79-1.92 (m, 2H), 1.66-1.77
(m, 1H), 1.08 (dd,
J = 6.27, 4.02 Hz, 6H).
Example 5
[0151]

(S)-8-((2-amino-4-methylpentyl)oxy)-6-methyl-5-oxo-5,6 dihydrobenzo[c][2,7]naphthyridine-9-carbonitrile
[0152]

Part A. (S)-tert-butyl (1-((9-cyano-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0153] In a 25 mL sealed tube, (
S)-
tert-butyl (1-((9-bromo-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (150 mg, 0.297 mmol) (as
prepared in Ex. 3, Part A) was taken up in DMA (4 mL). To this mixture was added CuCN
(53.3 mg, 0.595 mmol) and the mixture heated at 150° C for 24 h. The reaction mixture
was cooled to room temperature and diluted with ethyl acetate (20 mL) and filtered
through diatomaceous earth (Celite
®). The ethyl acetate solution was washed with brine (10 mL) and water (10 mL). The
organic layer was dried over sodium sulfate and concentrated under reduced pressure
to afford the crude product as gummy solid which was carried forward without further
purification. LC/MS (ESI)
m/
e 451.2 [(M+H)
+, calcd for C
25H
31N
4O
4, 451.5]; LC/MS retention time (method B):
tR = 2.02 min.

Part B. (S)-8-((2-amino-4-methylpentyl)oxy)-6-methyl-5-oxo-5,6 dihydrobenzo[c] [2,7]naphthyridine-9-carbonitrile
[0154] In a 25 mL round-bottomed flask, (
S)-
tert-butyl (1-((9-cyano-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (75 mg, 0.167 mmol) was
taken up in MeOH (4 mL) and cooled to 0 °C. The mixture was treated with 4M solution
of HCl in 1,4-dioxane (2 mL, 8 mmol) and stirred for 2 h at RT. The MeOH was removed
and the crude product was dissolved in EtOAc (20 mL). The ethyl acetate layer was
washed with water (2x10 mL) and dried over sodium sulfate. Removal of the solvent
gave crude product which was purified by silica-gel column (MeOH-CHCl
3 mixture) to obtain (
S)-8-((2-amino-4-methylpentyl)oxy)-6-methyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridine-9-carbonitrile (4 mg, 0.01 mmol, 7% yield over 2 steps) as a yellow
solid. LC/MS (ESI)
m/
e 351.2. [(M+H)
+, calcd for C
20H
21N
4I
2, 351.4]; LC/MS retention time (method B):
tR = 1.43 min. HPLC retention time (method A):
tR = 9.69 min; HPLC retention time (method B):
tR = 9.31 min.
1H NMR (400 MHz,
CD3OD) δ ppm 9.56 (bs, 1H), 8.93 (s, 2H), 8.37 (d,
J = 4.77 Hz, 1H), 7.25 (s, 1H), 4.63 (dd,
J = 10.67, 3.14 Hz, 1H), 4.47 (dd,
J = 10.79, 6.02 Hz, 1H), 3.81-3.89 (m, 4H), 1.83-1.91 (m, 2H), 1.72 (t,
J = 6.53 Hz, 1H), 1.08 (d,
J = 5.02 Hz, 6H).
Example 6
(S)-8-((2-amino-4-methylpentyl)oxy)-9-cyclopropyl-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0155]

Part A: (S)-tert-butyl (1-((9-cyclopropyl-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0156] A mixture of (
S)-
tert-butyl (1-((9-bromo-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (150 mg, 0.297 mmol) (as
prepared in Ex. 3, Part A), cyclopropylboronic acid (28.1 mg, 0.327 mmol), tetrakis(triphenylphosphine)palladium
(17.2 mg, 0.015 mmol) and Cs
2CO
3 (291 mg, 0.892 mmol) in toluene (5 mL) and water (0.43 mL) mixture was purged with
nitrogen for 5 min then heated at 90°C overnight (16 h). After cooling, toluene was
removed under reduced pressure and the product was extracted with ethyl acetate (20
mL). The organic phase was washed with brine (2x20 mL), dried over Na
2SO
4, and concentrated under reduced pressure. The residue was purified by silica-gel
column chromatography (EtOAc-hexane) to afford (S)-
tert-butyl (1-((9-cyclopropyl-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (70 mg, 0.150 mmol, 51%
yield) as an off-white gummy solid. LC/MS (ESI)
m/
z 466.4 [(M+H)
+, calcd for C
27H
36N
3O
4 466.3]; LC/MS retention time (method E): t
R = 1.19 min.

Part B: (S)-8-((2-amino-4-methylpentyl)oxy)-9-cyclopropyl-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0157] To a solution of (
S)-
tert-butyl (1-((9-cyclopropyl-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (60 mg, 0.129 mmol) in
MeOH (4 mL), at 0 °C was added a 4M solution of HCl in 1,4-dioxane (2 mL, 8 mmol).
The resultant solution was stirred for 2 h at RT. The methanol was removed under reduced
pressure and the residue was extracted with ethyl acetate (2x5 mL). The organic phase
was washed with saturated aqueous NaHCO
3 (2x5 mL), dried over Na
2SO
4, and concentrated under reduced pressure. The residue was purified by silica-gel
column (MeOH-CHCl
3) to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-9-cyclopropyl-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (8 mg, 0.022 mmol, 17% yield) as an off-white solid. LC/MS (ESI)
m/
z 366.2 [(M+H)
+, calcd for C
22H
28N
3O
2 366.2]; LC/MS retention time (method B): t
R = 1.34 min. HPLC retention time (method B):
tR = 4.87 min and HPLC retention time (method A):
tR = 9.18 min.
1H NMR (400 MHz,
CDCl3) δ ppm 9.47 (s, 1H), 8.75 (d,
J = 5.7 Hz, 1H), 8.28 (d,
J = 5.7 Hz, 1H), 7.96 (s, 1H), 7.06 (s, 1H), 4.27 (m, 1H), 4.06-4.15 (m, 1H), 3.84
(s, 3H), 3.38-3.48 (m, 1H), 2.23-2.38 (m, 1H), 1.83-1.94 (m, 1H), 1.56-1.67 (m, 1H),
1.46-1.55 (m, 1H), 1.00-1.08 (m, 6H), 0.79-0.94 (m, 4H).
Example 7
(S)-8-(2-amino-4-methylpentyloxy)-9-hydroxy-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0158]

Part A. (S)-8-(2-amino-4-methylpentyloxy)-9-hydroxy-6 methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0159] A mixture of (
S)-
tert-butyl (1-((9-bromo-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.05 g, 0.099 mmol) (as
prepared in Ex. 3, Part A),
tetra-N-butylammonium hydroxide.30 H
2O (0.463 g, 1.784 mmol) and water (1.5 mL) was added over 0.1 h to a stirred solution
of copper(I) iodide (1.89 mg, 9.91 µmol) and 2-methyl 8-quinolinol (3.16 mg, 0.020
mmol) in DMSO (1 mL). The reaction mixture was heated to 120 °C and stirred for 14
h. The resulting mixture was cooled to room temperature. The crude product was purified
by reverse phase HPLC (10 mM ammonium acetate) to afford a (
S)-8-((2-amino-4-methylpentyl)oxy)-9-hydroxy-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (0.004 g, 0.011 mmol, 12% yield) as a brown solid. LC/MS (ESI)
m/
e 342.2 [(M+H)
+, calcd for C
19H
24N
3O
3, 342.2]; HPLC retention time (method F):
tR = 1.62 min. HPLC retention time (method B):
tR = 5.88 min.
1H NMR (400 MHz,
CD3OD) δ 9.39 (s, 1H), 8.62 (d,
J = 6.00 Hz, 1H), 7.96 (d,
J = 5.60 Hz, 1H), 7.56 (s, 1H), 6.73 (s, 1H), 3.80 (s, 3H), 3.67-3.70 (m, 1H), 3.49-3.59
(m, 2H), 1.81-1.85 (m, 1H), 1.56-1.63 (m, 2H), 1.05 (d,
J = 6.80 Hz, 3H), 0.98 (d,
J = 6.80 Hz, 3H).
Example 8
(S)-8-((2-amino-4-methylpentyl)oxy)-6-isopropylbenzo[c][2,7]naphthyridin-5(6H)-one
[0160]

Part A. 4-(4-chloro-2-fluorophenyl)-N-isopropylnicotinamide
[0161] To a solution of 4-(4-chloro-2-fluorophenyl)nicotinic acid (400 mg, 1.590 mmol) (prepared
as in Ex. 2, Part A) in DMF (6 mL) cooled to 0 °C was added EDC (457 mg, 2.384 mmol)
and HOBT (487 mg, 3.18 mmol) and the mixture was stirred for 5 min. To the resultant
solution DIPEA (0.83 mL, 4.77 mmol) followed by propan-2-amine (470 mg, 7.95 mmol)
were added and the mixture was stirred at room temperature for 12 h. The reaction
mixture was treated with ice and extracted with ethyl acetate (3x10 mL). The combined
organic layers were washed with brine (1x10 mL), dried (Na
2SO
4) and concentrated under reduced pressure to afford 4-(4-chloro-2-fluorophenyl)-N-isopropylnicotinamide
(480 mg, 1.64 mmol, 100%) as an off-white solid. LC/MS (ESI)
m/
e 293.2 [(M+H)
+, calcd for C
15H
15ClFN
2O 293.1]; LC/MS retention time (method C):
tR = 1.84 min.

Part B. 8-chloro-6-isopropylbenzo[c][2,7]naphthyridin-5(6H)-one
[0162] To a suspension of sodium hydride (79 mg, 3.28 mmol) in THF (8 mL) at 0 °C was added
a solution of 4-(4-chloro-2-fluorophenyl)-N-isopropylnicotinamide (480 mg, 1.640 mmol)
in THF (10 mL) dropwise over a period of 10 min. The reaction mixture was stirred
at 0 °C for 1 h and then warmed to room temperature and stirred for an additional
1 h. The reaction mixture was then treated with ice and extracted with ethyl acetate
(3x5 mL). The combined organic layers were washed with brine (1x5 mL), dried (Na
2SO
4) and concentrated under reduced pressure to afford crude 8-chloro-6-isopropylbenzo[
c][2,7]naphthyridin-5(67H7)-one (250 mg, 0.917 mmol, 56% yield). LC/MS (ESI)
m/
e 273.0 [(M+H)
+, calcd for C
15H
14ClN
2O 273.1]; LC/MS retention time (method C):
tR = 1.98 min;
1H NMR (400 MHz,
CDCl3) δ ppm 9.67 (s, 1H), 8.70 (d,
J = 6.0 Hz, 1H), 8.17 - 8.19 (d,
J= 8.4 Hz, 1H), 7.92 -7.94 (d,
J = 5.6 Hz, 1H), 7.62 (d,
J = 1.6 Hz, 1H), 7.26 - 7.31 (dd,
J = 8.8, 2.0 Hz, 1H), 3.21 - 3.28 (m, 1H), 1.71 (d,
J = 6.8 Hz, 6H).

Part C. (S)-tert-butyl (1-((6-isopropyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0163] To a solution 8-chloro-6-isopropylbenzo[
c][2,7]naphthyridin-5(67H7)-one (250 mg, 0.917 mmol) in toluene (2 mL) at room temperature
was added cesium carbonate (448 mg, 1.375 mmol) and di-
tert-butyl(2',4',6'-triisopropyl-[1,1-biphenyl]-2-yl)phosphine (234 mg, 0.550 mmol) and
the mixture was degassed for 5 min. The mixture was then treated with
N-Boc-L-leucinol (591 mg, 2.75 mmol) followed by palladium(II)acetate (61.7 mg, 0.275
mmol) and degassed for another 10 min. The reaction mixture was sealed and heated
at 80 °C. The reaction mixture was then cooled to room temperature and filtered through
diatomaceous earth (Celite
®). The bed was washed with ethyl acetate and the combined filtrate was concentrated
under reduced pressure to afford crude product which was purified by combi flash (gradient
of ethyl acetate and petroleum ether) afford (
S)-
tert-butyl (1-((6-isopropyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (160 mg, 0.198 mmol, 21%
yield) as an off-white solid. LC/MS (ESI)
m/
e 454.2 [(M+H)
+, calcd for C
26H
36N
3O
4 454.3]; LC/MS retention time (method C):
tR = 2.17 min.

Part D. (S)-8-((2-amino-4-methylpentyl)oxy)-6-isopropylbenzo[c][2,7]naphthyridin-5(6H)-one
[0164] To a solution of ((
S)-
tert-butyl (1-((6-isopropyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (160mg, 0.353 mmol) in
anhydrous dichloromethane (4 mL) was added a 2 M solution of HCl in diethyl ether
(0.88 mL, 1.76 mmol) dropwise at 0° C. The reaction mixture was allowed to warm to
room temperature and stirred for 2 h. The reaction mixture was then concentrated under
reduced pressure to afford crude product which was purified by preparative HPLC (10
mM ammonium acetate in water ; acetonitrile) to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-6-isopropylbenzo[
c][2,7]naphthyridin-5(6
H)-one (45 mg, 0.127 mmol, 36% yield) as an off-white solid. LC/MS (ESI)
m/
e 354.2 [(M+H)
+, calcd for C
21H
28N
3O
2 354.2]; LC/MS retention time (method C):
tR = 1.81 min; HPLC retention time (method A):
tR = 8.85 min; HPLC retention time (method B):
tR = 9.50 min.
1H NMR (400 MHz,
CD3OD) δ ppm 9.43 (d,
J = 0.75 Hz, 1H), 8.75 (d,
J = 5.77 Hz, 1H), 8.42 (d,
J = 9.04 Hz, 1H), 8.22 (d,
J = 5.52 Hz, 1H), 7.30 (d,
J = 2.26 Hz, 1H), 7.10 (dd,
J = 8.78, 2.26 Hz, 1H), 5.26 - 5.43 (m, 1H), 4.16 (dd,
J = 9.16, 3.89 Hz, 1H), 3.98 (dd,
J = 9.29, 7.03 Hz, 1H), 3.27 - 3.31 (m, 1H), 1.81 - 1.92 (m, 1H), 1.73 (d,
J = 7.03 Hz, 6H), 1.41 - 1.51 (m, 2H), 1.02 (dd,
J = 9.54, 6.53 Hz, 6H).
Example 9
(S)-6-allyl-8-((2-amino-4-methylpentyl)oxy)benzo[c][2,7]naphthyridin-5(6H)-one
[0165]

Part A. 4-(4-chloro-2-fluorophenyl)-N-cyclopropylnicotinamide
[0166] To a solution of 4-(4-chloro-2-fluorophenyl)nicotinic acid (500 mg, 1.987 mmol) (prepared
as in Ex. 2, Part A) in DMF (6 mL) cooled to 0 °C was added EDC (571 mg, 2.98 mmol)
and HOBT (609 mg, 3.97 mmol) and the mixture was stirred for 5 min. To the resultant
solution DIPEA (1.04 mL, 5.96 mmol) followed by cyclopropanamine (567 mg, 9.93 mmol)
was added and the mixture was stirred at room temperature for 12 h. The reaction mixture
was treated with ice and extracted with ethyl acetate (3x10 mL). The combined organic
layers were washed with brine (1x10 mL), dried (Na
2SO
4) and concentrated under reduced pressure to afford 4-(4-chloro-2-fluorophenyl)-N
cyclopropylnicotinamide (480 mg, 1.65 mmol, 83% yield). LC/MS (ESI)
m/
e 291.0 [(M+H)
+, calcd for C
15H
13ClFN
2O 291.1]; LC/MS retention time (method C):
tR = 1.79 min.

Part B. 8-chloro-6-cyclopropylbenzo[c][2,7]naphthyridin-5(6H)-one
[0167] To a suspension of sodium hydride (72.6 mg, 3.03 mmol) in THF (8 mL) at 0 °C was
added a solution of 4-(4-chloro-2-fluorophenyl)-
N-cyclopropylnicotinamide (440 mg, 1.51 mmol) in THF (10 mL) dropwise over a period
of 10 min. The reaction mixture was stirred at 0 °C for 1 h and then warmed to room
temperature and stirred for another 1 h. The reaction mixture was then treated with
ice and extracted with ethyl acetate (3x5 mL). The combined organic layers were washed
with brine (2x5 mL), dried (Na
2SO
4) and concentrated under reduced pressure to afford crude 8-chloro-6-cyclopropylbenzo[
c][2,7]naphthyridin-5(
6H)-one (340 mg, 1.26 mmol, 83% yield) as an off-white solid. LC/MS (ESI)
m/
e 271.0 [(M+H)
+, calcd for C
15H
12ClN
2O 271.1]; LC/MS retention time (method C):
tR = 1.89 min.

Part C. (S)-tert-butyl (1-((6-cyclopropyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0168] To a solution 8-chloro-6-cyclopropylbenzo[
c][2,7]naphthyridin-5(6
H)-one (200 mg, 0.739 mmol) in toluene (2 mL) at room temperature was added cesium
carbonate (361 mg, 1.108 mmol) and di-
tert-butyl(2',4',6'-triisopropyl-[1,1'-biphenyl]-2-yl)phosphine (188 mg, 0.443 mmol) and
the mixture was degassed with nitrogen for 5 min. The mixture was then treated with
N-Boc-L-leucinol (477 mg, 2.216 mmol) followed by palladium(II)acetate (49.8 mg, 0.222
mmol) and degassed for another 10 min. The reaction mixture was sealed and heated
at 80 °C. After overnight stirring the reaction mixture was cooled to room temperature
and filtered through diatomaceous earth (Celite
®). The bed was washed with ethyl acetate and the combined filtrate was concentrated
under reduced pressure to afford crude product which was purified by combi flash (ethyl
acetate and petroleum ether) to afford (
S)-
tert-butyl (1-((6-cyclopropyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (100 mg, 0.195 mmol, 26%
yield) as an off-white solid. LC/MS (ESI)
m/
e 452.2 [(M+H)
+, calcd for C
26H
14N
3O
4 452.3]; LC/MS retention time (method C):
tR = 2.11 min.

Part D. (S)-6-allyl-8-((2-amino-4-methylpentyl)oxy)benzo[c][2,7]naphthyridin-5(6H)-one
[0169] To a solution of (
S)-
tert-butyl (1-((6-cyclopropyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (100 mg, 0.221 mmol) in
anhydrous dichloromethane (2 mL) was added a 2 M solution of HCl in diethyl ether
(0.176 mL, 0.353 mmol) dropwise at 0 °C. The reaction mixture was allowed to warm
to room temperature and stirred for 2 h. The reaction mixture was then concentrated
under reduced pressure to afford crude product which was purified by preparative HPLC
(0.1% TFA in water) to afford (
S)-6-allyl-8-((2-amino-4-methylpentyl)oxy)benzo[
c][2,7]naphthyridin-5(6
H)-one (8 mg, 22.76 mmol, 10% yield) as a yellow solid. LC/MS (ESI)
m/
e 352.2 [(M+H)
+, calcd for C
21H
26N
3O
2 352.2]; LC/MS retention time (method C):
tR = 1.80 min; HPLC retention time (method A):
tR = 8.06 min; HPLC retention time (method B):
tR = 9.21 min.
1H NMR (400 MHz,
CD3OD) δ ppm 9.56 (s, 1 H), 8.85 (d,
J= 6.27 Hz, 1H), 8.55 (d,
J= 9.04 Hz, 1H), 8.48 (d,
J = 6.27 Hz, 1H), 7.20 (dd,
J = 8.91, 2.38 Hz, 1H), 7.14 (d,
J = 2.26 Hz, 1H), 6.08 (dd,
J = 17.32, 10.54 Hz, 1H), 5.28 (dd,
J = 10.54, 1.00 Hz, 1H), 5.18 (dd,
J = 17.32, 1.25 Hz, 1H), 5.09 - 5.13 (m, 2H), 4.44 (dd,
J = 10.54, 3.26 Hz, 1H), 4.27 (dd,
J= 10.42, 6.40 Hz, 1H), 3.77 (dd,
J = 6.78, 3.51 Hz, 1H), 1.64 - 1.88 (m, 3H), 1.07 (dd,
J= 6.40, 4.89 Hz, 6H).
Example 10
(S)-8-((2-amino-4-methylpentyl)oxy)-7,9-dichloro-6-methylbenzo[c][2,7]naphthyridin-5(6H) one
[0170]

Part A. (S)-tert-butyl (1-((7,9-dichloro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0171] To a stirred solution of (
S)-
tert-butyl (4-methyl-1-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (0.120 g, 0.282 mmol) (prepared
as in Ex. 2, Part D) in anhydrous acetonitrile (2 mL) under nitrogen was added
N-chlorosuccinimide (0.045 g, 0.338 mmol) and the solution was heated at 85 °C for
12 h. The reaction mixture was diluted with water (10 mL) and extracted with ethyl
acetate (2x20 mL). The combined organic layers were dried over sodium sulfate and
evaporated under reduced pressure to afford crude product which was purified by preparative
TLC (ethyl acetate in petroleum ether) to afford (
S)-
tert-butyl (1-((7,9-dichloro-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (120 mg, 0.243 mmol, 86%
yield, with 55% purity by LC/MS) as a yellow solid. LC/MS (ESI)
m/
e 494.2 [(M+H)
+, calcd for C
24H
30Cl
2N
3O
4 494.1]; LC/MS retention time (method A):
tR = 2.24 min.

Part B. (S)-8-((2-amino-4-methylpentyl)oxy)-7,9-dichloro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0172] To a solution of (
S)-
tert-butyl (1-((7,9-dichloro-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.120 g, 0.243 mmol) in
anhydrous methanol (5 mL) was added a 4M solution of HCl in 1,4-1,4-dioxane (2 mL,
8 mmol) dropwise at 0° C. The reaction mixture was allowed to warm to room temperature
and stirred for 2 h. The reaction mixture was then concentrated under reduced pressure
to afford crude compound which was purified by preparative HPLC (10 mM ammonium acetate
in water; acetonitrile) to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-7,9-dichloro-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (28 mg, 0.063 mmol, 26% yield) as a yellow solid. LC/MS (ESI)
m/
e 394.2 [(M+H)
+, calcd for C
19H
22Cl
2N
3O
2 394.1]; LC/MS retention time (method A):
tR = 1.48 min; HPLC retention time (method A):
tR = 5.21 min; HPLC retention time (method B):
tR = 5.73 min.
1H NMR (400 MHz,
CD3OD) δ ppm 9.50 (d,
J= 0.75 Hz, 1H), 8.87 (d,
J = 5.52 Hz, 1H), 8.58 (s, 1 H), 8.32 (d,
J = 5.27 Hz, 1H), 4.17 (dd,
J= 9.03, 4.02 Hz, 1H), 4.05 (dd,
J = 9.03, 7.28 Hz, 1H), 3.93 (s, 3H), 3.37 - 3.43 (m, 1H), 1.82 - 1.93 (m, 1H), 1.38
- 1.57 (m, 2H), 0.99 - 1.05 (m, 6H).
Example 11
(S)-8-((2-amino-4-methylpentyl)oxy)-6-benzylbenzo[c][2,7]naphthyridin-5(6H)-one
[0173]

[0174] Part A.
N-benzyl-4-(4-chloro-2-fluorophenyl)nicotinamide (
S)-8-(2-amino-4-methylpentyloxy)-6-benzylbenzo[
c][2,7]naphthyridin-5(6
H)-one To a solution of 4-(4-chloro-2-fluorophenyl)nicotinic acid (600mg, 2.38 mmol)
(as prepared in Ex. 2, Part A) in DMF (6 mL) cooled to 0 °C was added EDC (457 mg,
2.38 mmol) and HOBT (365 mg, 2.38 mmol) and the mixture was stirred for 5 min. To
the resultant solution was added DIPEA (0.416 mL, 2.384 mmol) followed by benzyl amine
(307 mg, 2.86 mmol) and the mixture was stirred at room temperature for 12 h. The
reaction mixture was treated with ice and extracted with ethyl acetate (3x10 mL).
The combined organic layers were washed with brine (1x10 mL), dried (Na
2SO
4) and concentrated under reduced pressure to afford
N-benzyl-4-(4-chloro-2-fluorophenyl)nicotinamide (680 mg, 2.00 mmol, 84% yield). LC/MS
(ESI)
m/
e 341.0 [(M+H)
+, calcd for C
19H
15ClFN
2O 341.1]; LC/MS retention time (method A):
tR = 1.73 min.

Part B. 6-benzyl-8-chlorobenzo[c][2,7]naphthyridin-5(6H)-one
[0175] To a suspension of sodium hydride (96 mg, 3.99 mmol) in THF (13 mL) at 0 °C was added
a solution of
N-benzyl-4-(4-chloro-2-fluorophenyl)nicotinamide (680 mg, 1.995 mmol) in THF (10 mL)
dropwise over a period of 10 min. The reaction mixture was stirred at 0 °C for 1 h
and then warmed to room temperature and stirred for another 1 h. The reaction mixture
was then treated with ice and extracted with ethyl acetate (3x5 mL). The combined
organic layers were washed with brine (1x5 mL), dried (Na
2SO
4) and concentrated under reduced pressure to afford crude 6-benzyl-8-chlorobenzo[
c][2,7]naphthyridin-5(6
H)-one (640 mg, 2.00 mmol, 100%). LC/MS (ESI)
m/
e 321.0 [(M+H)
+, calcd for C
19H
14ClN
2O 321.0]; LC/MS retention time (method A):
tR = 1.95 min.

Part C. (S)-tert-butyl (1-((6-benzyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0176] To a solution 6-benzyl-8-chlorobenzo[
c][2,7]naphthyridin-5(6
H)-one (640mg, 2.00 mmol) in toluene (12 mL) at room temperature, was added cesium
carbonate (975 mg, 2.99 mmol) and
N-Boc L-Leucinol (1287 mg, 5.99 mmol) and the mixture was degassed with nitrogen for
5 min. The mixture was then treated with di-
tert-butyl(2',4',6'-triisopropyl-[1,1'-biphenyl]-2-yl)phosphine (508 mg, 1.197 mmol) followed
by palladium(II)acetate (448 mg, 2.00 mmol) and degassed for another 10 min. The reaction
mixture was sealed and heated at 80 °C. After overnight stirring the reaction mixture
was cooled to room temperature and filtered through diatomaceous earth (Celite
®). The bed was washed with ethyl acetate and the combined filtrate was concentrated
under reduced pressure to afford crude product which was purified by combi flash (ethyl
acetate/petroleum ether) to afford (
S)-
tert-butyl (1-((6-benzyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (500mg, 0.738 mmol, 37%
yield) as an off-white solid. LC/MS (ESI)
m/
e 502.3 [(M+H)
+, calcd for C
30H
36N
3O
4 502.4]; LC/MS retention time (method D):
tR = 1.26 min.

Part D. (S)-8-((2-amino-4-methylpentyl)oxy)-6-benzylbenzo[c][2,7]naphthyridin-5(6H)-one
[0177] To a solution of (
S)-
tert-butyl (1-((6-benzyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (35mg, 0.070 mmol) in anhydrous
dichloromethane (1 mL) was added a 2 M solution of HCl in diethyl ether (0.17 mL,
0.349 mmol) dropwise at 0° C. The reaction mixture was allowed to warm to room temperature
and stirred for 2 h. The reaction mixture was then concentrated under reduced pressure
to afford crude product which was purified by preparative TLC (ethyl acetate in petroleum
ether) to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-6-benzylbenzo[
c][2,7]naphthyridin-5(6
H)-one (10 mg, 0.024 mmol, 35% yield) as a light yellow solid. LC/MS (ESI)
m/
e 402.2 [(M+H)
+, calcd for C
25H
28N
3O
2 402.2]; LC/MS retention time (method C):
tR = 1.77 min; HPLC retention time (method A):
tR = 5.54 min; HPLC retention time (method B):
tR = 6.17 min.
1H NMR (400 MHz
CD3OD) δ ppm 9.61 (br. s., 1H), 8.87 (d,
J = 4.52 Hz, 1H), 8.53 (d,
J = 9.04 Hz, 1H), 8.47 (d,
J = 6.02 Hz, 1H), 7.28 - 7.38 (m, 5H), 7.15 (dd,
J = 8.91, 2.38 Hz, 1H), 7.04 (d,
J = 2.26 Hz, 1H), 5.72 (d,
J = 5.77 Hz, 2H), 4.27 (dd,
J = 10.54, 3.26 Hz, 1H), 4.10 (dd,
J = 10.42, 6.40 Hz, 1H), 3.69 (dd,
J = 6.65, 3.14 Hz, 1H), 1.68 - 1.81 (m, 1H), 1.57 - 1.67 (m, 2H), 1.00 - 1.05 (m, 6H).
Example 12
(S)-8-((2-amino-4-methylpentyl)oxy)-6-(2-methoxyethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0178]

Part A. 4-(4-chloro-2-fluorophenyl)nicotinamide
[0179] To a stirred solution of 4-(4-chloro-2-fluorophenyl)nicotinic acid (1.1 g, 4.37 mmol)
(as prepared in Ex. 2, Part A) in anhydrous DMF (10 mL) cooled to 0° C was added HOBT
(1.339 g, 8.74 mmol), EDC (1.257 g, 6.56 mmol), DIEA (3.05 mL, 17.49 mmol) followed
by ammonium chloride (1.169 g, 21.86 mmol). The reaction mixture was allowed to warm
to RT and stirred for 12 h under a nitrogen atmosphere. The reaction mixture was diluted
with water (50 mL) and extracted with ethyl acetate (2x100 mL). The combined organic
layers were dried over sodium sulfate and concentrated under reduced pressure to afford
4-(4-chloro-2-fluorophenyl)nicotinamide (0.900 g, 3.59 mmol, 82% yield) LC/MS (ESI)
m/
e 251 [(M+H)
+,calcd for C
12H
9ClFN
2O 251]; LC/MS retention time (method A):
tR = 1.34 min.

Part B. 8-chlorobenzo[c][2,7]naphthyridin-5(6H)-one
[0180] To a solution of 4-(4-chloro-2-fluorophenyl)nicotinamide (0.9 g, 3.59 mmol) in THF
(20 mL) at 0 °C was added sodium hydride (0.258 g, 10.77 mmol) and the reaction mixture
was stirred at 0 °C for 1 h and then warmed to room temperature and stirred overnight
(14 h). The reaction mixture was then quenched with ice and extracted with ethyl acetate
(2x100 mL). The combined organic layers were washed with brine (1x100 mL), dried (Na
2SO
4) and concentrated under reduced pressure to afford crude 8-chlorobenzo[
c][2,7]naphthyridin-5(6
H)-one (0.80 g, 3.47 mmol, 97% yield). LC/MS (ESI)
m/
e 231.2 [(M+H)
+, calcd for C
12H
8ClN
2O 231]; LC/MS retention time (method D):
tR = 0.61 min.

Part C. 8-chloro-6-(2-methoxyethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0181] To a stirred solution of 8-chlorobenzo[
c][2,7]naphthyridin-5(6
H)-one (0.150 g, 0.650 mmol) in anhydrous DMF (2 mL) at 0 °C was added 2-bromoethyl
methyl ether (0.090 g, 0.650 mmol) under nitrogen. The reaction mixture was allowed
to warm to RT and stirred for 12 h. The reaction mixture was diluted with water (10
mL) and extracted with ethyl acetate (2 x 20 mL). The combined organic layers were
dried over sodium sulfate and concentrated under reduced pressure to afford 8-chloro-6-(2-methoxyethyl)benzo[
c][2,7]naphthyridin-5(6
H)-one (150mg, 0.520 mmol, 80% yield). LC/MS (ESI)
m/
e 289.1 [(M+H)
+, calcd for C
15H
13ClN
2O
2 289.1]; LC/MS retention time (method A):
tR = 1.65 min.

Part D. (S)-tert-butyl (1-((6-(2-methoxyethyl)-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0182] To a solution 8-chloro-6-cyclopropylbenzo[
c][2,7]naphthyridin-5(6
H)-one (100 mg, 0.346 mmol) in toluene (5 mL) at room temperature was added cesium
carbonate (169 mg, 0.520 mmol) and
N-Boc-L-leucinol (226 mg, 1.039 mmol) and the mixture was degassed with nitrogen for
5 min. The mixture was then treated with di-
tert-butyl(2',4',6'-triisopropyl-[1,1'-biphenyl]-2-yl)phosphine (47.8 mg, 0.208 mmol)
followed by palladium(II)acetate (23.3 mg, 0.104 mmol) and degassed for another 10
min. The reaction mixture was sealed and heated at 80 °C. After overnight stirring
the reaction mixture was cooled to room temperature and filtered through diatomaceous
earth (Celite
®). The bed was washed with ethyl acetate (15 mL) and the filtrate was concentrated
under reduced pressure to afford crude product which was purified by combi flash (gradient
of ethyl acetate and petroleum ether) afford (
S)-
tert-butyl (1-((6-(2-methoxyethyl)-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (80 mg, 0.170 mmol, 49%
yield) as a brown gum. LC/MS (ESI)
m/
e 470.3 [(M+H)
+, calcd C
26H
36N
3O
5 470.3]; LC/MS retention time (method A):
tR = 2.02 min.

Part E. (S)-8-((2-amino-4-methylpentyl)oxy)-6-(2 methoxyethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0183] To a solution of (
S)-
tert-butyl (1-((6-(2-methoxyethyl)-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.080 g, 0.170 mmol) in
anhydrous methanol (5 mL) was added a 4M solution of HCl in 1,4-dioxane (0.21 mL,
0.85 mmol) dropwise at 0°C. The reaction mixture was allowed to warm to room temperature
and stirred for 2 h. The reaction mixture was concentrated under reduced pressure
to afford crude compound which was purified by preparative HPLC (10 mM ammonium acetate
in water: acetonitrile) to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-6-(2-methoxyethyl)benzo[c][2,7]naphthyridin-5(6
H)-one (20 mg, 0.054 mmol, 32% yield) a white solid. LC/MS (ESI)
m/
e 370.2 [(M+H)
+, calcd for C
21H
28N
3O
3 370.2]; LC/MS retention time (method A):
tR = 1.34 min; HPLC retention time (method A):
tR = 8.36 min; HPLC retention time (method B):
tR = 8.78 min.
1H NMR (400 MHz,
CD3OD) δ ppm 9.45 (s, 1H), 8.76 (d,
J= 5.77 Hz, 1H), 8.40 (d,
J = 9.03 Hz, 1H,), 8.23 (d,
J = 6.02 Hz, 1H), 7.29 (d,
J = 2.26 Hz, 1H), 7.11 (d,
J= 8.78 Hz, 1H), 4.61 (t,
J = 5.65 Hz, 2H), 4.36 (s, 1H), 4.20 (s, 1H), 3.81 (t,
J= 5.77 Hz, 2H), 3.63 - 3.71 (m, 1H), 3.37 (s, 3H), 1.86 (m, 1H), 1.67 (qt,
J = 14.01, 7.09 Hz, 2H), 1.06 (d,
J= 5.77 Hz, 6H).
Example 13
(S)-8-((2-amino-4-methylpentyl)oxy)-6-(cyclopropylmethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0184]

Part A. 8-chloro-6-(cyclopropylmethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0185] To a stirred solution of 8-chlorobenzo[
c][2,7]naphthyridin-5(6
H)-one (100 mg, 0.434 mmol) (as prepared in Ex. 12, Part B) in anhydrous DMF (2 mL)
at 0 °C was added cyclopropyl methyl bromide (0.088 g, 0.650 mmol) under nitrogen.
The reaction mixture was allowed to warm to RT and stirred for 12 h. The reaction
mixture was diluted with water (10 mL) and extracted with ethyl acetate (2x20 mL).
The combined organic layers were dried over sodium sulfate and concentrated under
reduced pressure to 8-chloro-6-(cyclopropylmethyl)benzo[c][2,7]naphthyridin-5(6
H)-one (100 mg, 0.351 mmol, 81 % yield, 53% pure by LC/MS). LC/MS (ESI)
m/
e 285.1 [(M+H)
+, calcd for C
16H
14ClN
2O 285.1]; LC/MS retention time (method D):
tR = 0.91 min.

Part B. (S)-tert-butyl (1-((6-(cyclopropylmethyl)-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0186] To a solution 8-chloro-6-(cyclopropylmethyl)benzo[c][2,7]naphthyridin-5(6
H)-one (100 mg, 0.351 mmol) in anhydrous toluene (5 mL) at room temperature was added
cesium carbonate (172 mg, 0.527 mmol) and Boc-L-leucinol (229 mg, 1.054 mmol) and
the mixture was degassed with nitrogen for 5 min. The mixture was then treated with
di-
tert-butyl(2',4',6'-triisopropyl-[1,1'-biphenyl]-2-yl)phosphine (48.5 mg, 0.211 mmol)
followed by palladium(II)acetate (23.65 mg, 0.105 mmol) and degassed for another 10
min. The reaction mixture was sealed and heated at 80 °C. After overnight stirring
the reaction mixture was cooled to room temperature and filtered through diatomaceous
earth (Celite
®). The bed was washed with ethyl acetate (15 mL) and the filtrate was concentrated
under reduced pressure to afford crude compound which was purified by preparative
HPLC (ethyl acetate in petroleum ether) to afford (
S)-
tert-butyl (1-((6-(cyclopropylmethyl)-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (80 mg, 0.172 mmol, 49%
yield) as a brown gummy solid. LC/MS (ESI)
m/
e 466.3 [(M+H)
+, calcd C
27H
36N
3O
4466.3]; LC/MS retention time (method A):
tR = 2.199 min.

Part C. (S)-8-((2-amino-4-methylpentyl)oxy)-6 (cyclopropylmethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0187] To a solution of (
S)-
tert-butyl (1-((6-(cyclopropylmethyl)-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.08 g, 0.172 mmol) in
anhydrous methanol (5 mL) was added a 4M solution of HCl in 1,4-dioxane (2 mL, 65.8
mmol) dropwise at 0 °C. The reaction mixture was allowed to warm to room temperature
and stirred for 2 h. The reaction mixture was concentrated under reduced pressure
to afford crude compound which was purified by preparative HPLC (10 mM ammonium acetate
in water:acetonitrile) to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-6-(cyclopropylmethyl)benzo[
c][2,7]naphthyridin-5(6
H)-one (22 mg, 0.060 mmol, 35% yield) as a yellow gum. LC/MS (ESI)
m/
e 366.2 [(M+H)
+, calcd for C
22H
28N
3O
2 366.2]; LC/MS retention time (method A):
tR = 1.47 min; HPLC retention time (method A):
tR = 9.470 min; HPLC retention time (method B):
tR = 5.250 min.
1H NMR (400 MHz,
CD3OD) δ ppm 9.47 (d,
J = 0.50 Hz, 1H), 8.78 (d,
J= 5.77 Hz, 1H), 8.46 (d,
J= 9.04 Hz, 1H), 8.26 (d,
J= 5.52 Hz, 1H), 7.28 (d,
J= 2.26 Hz, 1H), 7.14 (dd,
J = 9.03, 2.26 Hz, 1H), 4.39 (d,
J= 6.78 Hz, 2H), 4.31 (dd,
J = 9.79, 3.76 Hz, 1H), 4.13 (dd,
J = 9.79, 6.78 Hz, 1H), 3.53 (dd,
J= 7.15, 3.64 Hz, 1H), 1.87 (m, 1H), 1.59 (q,
J = 13.72, 7.03 Hz, 2H), 1.36 - 1.45 (m, 1H), 1.04 (dd,
J = 7.28, 6.78 Hz, 6H), 0.57 - 0.63 (m, 4H).
Example 14
(S)-8-((2-amino-4-methylpentyl)oxy)-9-fluoro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0188]

Part A. 2-(4-chloro-2,5-difluorophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
[0189] To a solution of 1-bromo-4-chloro-2,5-difluorobenzene (200 mg, 0.879 mmol) in THF
(10 mL) cooled to -10 ° C was added isopropylmagnesium bromide (1M in THF, 1.055 mL,
1.055 mmol) dropwise and the reaction mixture was stirred at this temperature for
1 h. The reaction mixture was then warmed to 0 °C and stirred for another 1 h. The
resultant mixture was again cooled to -10 °C and treated dropwise with a solution
of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (196 mg, 1.055 mmol). The
reaction mixture was allowed to warm up to room temperature and treated with a saturated
solution of ammonium chloride (3 mL). The layers were separated and aqueous layer
was extracted with dichloromethane (2 x 2 mL). The combined organic layer was dried
over sodium sulfate, filtered and concentrated under reduced pressure to afford crude
compound which was purified by column chromatography on a silica (7:3 - Ethyl acetate:hexane)
to afford 2-(4-chloro-2,5-difluorophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
(150 mg, 0.546 mmol, 62% yield) as an oil.
1H NMR (400 MHz,
DMSO-d6) δ ppm 7.46 - 7.49 (m, 1H), 7.09 - 7.13 (m, 1 H), 1.35 (s, 12H).

Part B. methyl 4-(4-chloro-2,5-difluorophenyl)nicotinate
[0190] To a stirred solution of methyl 4-chloronicotinate (100 mg, 0.583 mmol) in a solvent
mixture of 1,4-dioxane:water (4:1, 20 mL) at room temperature under nitrogen atmosphere
was added potassium carbonate (62.6 mg, 0.453 mmol) followed by tetrabutylammonium
bromide (73.0 mg, 0.226 mmol). The resultant mixture was degassed with nitrogen for
10 min and treated with
N-(6-chloro-4-(trimethylstannyl)pyridin-2-yl)acetamide (60.4 mg, 0.181 mmol) followed
by bis(triphenylphosphine)palladium(II)chloride (10.60 mg, 0.015 mmol). The mixture
was degassed again for 1o min and heated at 80 °C for 8 h. The reaction mixture was
then cooled to room temperature and quenched with water (20 mL) and extracted with
ethyl acetate (5 mL). The organic layer was separated and washed with water (3x 5
mL), dried (Na
2SO
4) and concentrated under reduced pressure to afford crude methyl 4-(4-chloro-2,5-difluorophenyl)nicotinate
(400 mg, 0.592 mmol, 20% yield, 42 % pure by LC/MS). This was taken to the next step
without further purification. LC/MS (ESI)
m/
e 284.0 [(M+H)
+, calcd for C
13H
9ClF
2NO
2 284.02]; LC/MS retention time (method A):
tR = 1.82 min.

Part C. 4-(4-chloro-2,5-difluorophenyl)nicotinic acid
[0191] To a solution of methyl 4-(4-chloro-2,5-difluorophenyl)nicotinate (400 mg, 1.41 mmol)
in water:THF (1:1, 8 mL) was added LiOH (67.5 mg, 2.82 mmol) and the reaction mixture
was stirred at room temperature for 4 h. The reaction mixture was quenched with water
(5 mL) and washed with ethyl acetate (2x5 mL). The aqueous layer was separated and
acidified with 1.5N HCl and concentrated under reduced pressure to afford 4-(4-chloro-2,5-difluorophenyl)nicotinic
acid (180 mg, 0.541 mmol, 38% yield) as a solid. LC/MS (ESI)
m/
e 270 [(M+H)
+, calcd for C
12H
7ClF
2NO
2 270]; LC/MS retention time (method B):
tR = 1.48 min.

Part D. 4-(4-chloro-2,5-difluorophenyl)-N-methylnicotinamide
[0192] 4-(4-chloro-2,5-difluorophenyl)nicotinic acid (170 mg, 0.630 mmol) was taken in thionyl
chloride (0.14 mL, 1.89 mmol) and heated at 65 °C for 1 h. The solvent was evaporated
under reduced pressure to afford a crude oil which was dissolved in dichloromethane
and added to a mixture of methanamine hydrochloride (63.9 mg, 0.946 mmol) and DIEA
(0.11 mL, 0.63 mmol) in DCM (8 mL) dropwise at 0 °C. The reaction mixture was then
allowed to warm to room temperature and stirred for 7 h. The reaction mixture was
diluted with DCM (5 mL) and washed with water (3x 5 mL) followed by brine (1x10 mL).
The combined organic extracts were dried over sodium sulfate and concentrated under
reduced pressure to provide the crude product which was purified by preparative thin
layer chromatography (3:2 Ethyl acetate:hexane) to afford 4-(4-chloro-2,5-difluorophenyl)-
N-methylnicotinamide (90 mg, 0.264 mmol, 42% yield) as a white solid. LC/MS (ESI)
m/
e 283.0 [(M+H)
+, calcd for C
13H
10ClF
2N
2O 283.0]; LC/MS retention time (method A):
tR = 1.46 min.

Part E. 8-chloro-9-fluoro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0193] To a suspension of sodium hydride (56.6 mg, 1.42 mmol) in THF (5 mL) at 0 °C was
slowly added 4-(4-chloro-2,5-difluorophenyl)-
N-methylnicotinamide (100 mg, 0.354 mmol) in THF (5 mL). The resultant mixture was
stirred at room temperature for 1 h. The reaction was then quenched by addition of
cold water (1 mL) and extracted with ethyl acetate (2x2 mL). The combined organic
extracts were dried with sodium sulfate and concentrated under reduced pressure. The
residue was purified by column chromatography (1:1 ethyl acetate in petroleum ether)
to afford 8-chloro-9-fluoro-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (82 mg, 0.297 mmol, 84% yield) as white solid. LC/MS (ESI)
m/
e 262.5 [(M+H)
+, calcd for C
13H
9ClFN
2O 263.0]; LC/MS retention time (method D):
tR = 1.79 min; HPLC retention time (method A):
tR = 7.35 min; HPLC retention time (method B):
tR = 7.07 min.

Part F. (S)-tert-butyl (1-((9-fluoro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0194] To a stirred suspension of 8-chloro-9-fluoro-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (40 mg, 0.152 mmol), (
S)
-tert-butyl (1-hydroxy-4-methylpentan-2-yl)carbamate (39.7 mg, 0.183 mmol), di-
tert-butyl(2',4',6'-triisopropyl-[1,1'-biphenyl]-2-yl)phosphine (38.8 mg, 0.091 mmol) and
cesium carbonate (74.4 mg, 0.228 mmol) in toluene (4 mL) was added palladium(II)acetate
(10.26 mg, 0.046 mmol). Nitrogen gas was bubbled through the mixture for 5 min, and
then the reaction mixture was heated to 85 °C for 8 h. The reaction mixture was cooled
to room temperature and diluted with ethyl acetate (2 mL) and filtered through diatomaceous
earth (Celite'
®'). The filtrate was washed with water (2x2 mL) and brine (2x2 mL), dried over sodium
sulfate and concentrated under reduced pressure. The residue was purified via silica
gel column chromatography (60% ethyl acetate in hexanes) to afford (
S)-
tert-butyl (1-((9-fluoro-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (28 mg, 0.023 mmol, 15%
yield). LC/MS (ESI)
m/
e 444.2 [(M+H)
+, calcd for C
24H
31lFN
3O
4 444.2]; LC/MS retention time (method A):
tR = 2.02 min.

Part G. (S)-8-((2-amino-4-methylpentyl)oxy)-9-fluoro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0195] To a stirred solution of (
S)-
tert-butyl (1-((9-fluoro-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (25 mg, 0.056 mmol) in
diethyl ether (4 mL) was added a 2M solution of hydrochloric acid in diethyl ether
(42.5 µl, 0.085 mmol) at 0 °C dropwise over 10 min. The ice bath was removed and the
reaction mixture was stirred at room temperature for 2 h. The solvent was removed
and the crude material was taken up in water (5 mL). The aqueous layer was washed
with ethyl acetate (3 mL) and treated with 10 % NaHCO
3 (20 mL). The resultant solution was extracted with ethyl acetate (3x10 mL). The combined
organic layers were washed with water (2x10 mL), dried (sodium sulfate), filtered
and concentrated under reduced pressure to afford crude material which was purified
via preparative TLC (40% Ethyl acetate in Hexane) to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-9-fluoro-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (15 mg, 0.041 mmol, 73% yield) as a white solid. LC/MS (ESI)
m/
e 344.2 [(M+H)
+, calcd for C
19H
23FN
3O
2 344.2]; LC/MS retention time (method A):
tR = 1.35 min; HPLC retention time (method A):
tR = 8.31 min; HPLC retention time (method B):
tR = 8.85 min;
1H NMR (400 MHz,
CD3OD) δ ppm 9.66 - 9.71 (m, 1 H), 8.83 - 8.87 (m, 1 H), 7.90 - 7.95 (m, 1 H), 7.79 - 7.83
(m, 1 H), 6.91 - 6.95 (m, 1 H), 4.10 - 4.14 (m, 1 H), 3.89 - 3.95 (m, 1 H), 3.76 -
3.80 (m, 3 H), 3.35 - 3.44 (m, 1 H), 1.78 - 1.86 (m, 1 H), 1.39 (t,
J= 7.00 Hz, 2 H), 0.96 - 1.03 (m, 6 H).
Example 15
8-(2-amino-5,5,5-trifluoropentyloxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0196]

Part A. Tert-butyl 2-(diphenylmethyleneamino)-5,5,5-trifluoropentanoate
[0197] To a stirred solution of
tert-butyl 2-((diphenylmethylene)amino)acetate (1 g, 3.39 mmol) in THF (20 mL) cooled
to -78 °C under nitrogen atmosphere was added a 2M solution of LDA in THF (2.54 mL,
5.08 mmol) dropwise for 30 min. To this mixture was then added 3,3,3-trifluoropropyl
trifluoromethanesulfonate (1.083 g, 4.40 mmol). The reaction was gradually warmed
to rt and stirred for 4 h. The reaction mixture was quenched by addition of saturated
aqueous ammonium chloride at 0 °C. The reaction mixture was then extracted with ethyl
acetate (3x10 mL). The combined organic extracts were washed with water (1x10 mL)
and brine (1x10 mL), dried over sodium sulfate and then concentrated under reduced
pressure. The crude oil was purified by silica gel column chromatography (2% ethyl
acetate in hexane) to afford
tert-butyl 2-((diphenylmethylene)amino)-5,5,5-trifluoropentanoate (800 mg, 2.02 mmol,
60% yield) as a yellow oil. LC/MS (ESI)
m/
e 391.9 [(M+H)
+, calcd for C
22H
25F
3NO
2, 392.2]; LC/MS retention time (method E):
tR = 2.49 min.

Part B. 2-amino-5,5,5-trifluoropentanoic acid (hydrochloride salt)
[0198] A stirred solution of
tert-butyl 2-((diphenylmethylene)amino)-5,5,5-trifluoropentanoate (800 mg, 2.023 mmol)
in 50% aqueous HCl (0.123 mL, 2.023 mmol) was refluxed at 100 °C for 8 h. The reaction
mixture was cooled to rt and concentrated under reduced pressure to afford 2-amino-5,5,5-trifluoropentanoic
acid hydrochloride (400 mg, 1.82 mmol, 90% yield, 78% pure by LC/MS) as a white solid.
LC/MS (ESI)
m/
e 171.7 [(M+H)
+, calcd for C
5H
7F
3O
2, 172.1]; LC/MS retention time (method E):
tR = 0.80 min.

Part C. 2-(tert-butoxycarbonylamino)-5,5,5-trifluoropentanoic acid
[0199] To a stirred solution of 2-amino-5,5,5-trifluoropentanoic acid hydrochloride (400
mg, 1.503 mmol, 78% by LC/MS) in THF (8 mL) and water (8 mL) at rt was added K
2CO
3 (831 mg, 6.01 mmol) and the solution stirred for 10 min. To this mixture was added
Boc
2O (656 mg, 3.01 mmol). The reaction mixture was stirred for 8 h at rt then concentrated
under reduced pressure. The aqueous layer was washed with ethyl acetate (3x5 mL).
The aqueous layer was acidified with saturated citric acid solution (5 mL) and extracted
with ethyl acetate (3x8 mL). The combined organic layers were washed with water (3x5
mL) followed by brine solution (1x10 mL), dried over sodium sulfate and concentrated
under reduced pressure to afford 2-((tert-butoxycarbonyl)amino)-5,5,5-trifluoropentanoic
acid (500 mg, 1.84 mmol, 100% yield) as a colorless oil. The material was taken into
the next step without further purification.
1H NMR (400 MHz,
CDCl3) δ 5.04 (s, 1H), 4.38 (s, 1H), 2.15-2.28 (m, 2H), 1.91-1.95 (m, 2H), 1.46 (s, 9H).

Part D. Tert-butyl 5,5,5-trifluoro-1-hydroxypentan-2-ylcarbamate
[0200] To a stirred solution of 2-((
tert-butoxycarbonyl)amino)-5,5,5-trifluoropentanoic acid (500 mg, 1.843 mmol) in THF (15
mL) cooled to -10 °C under nitrogen atmosphere was added N-methylmorphline (0.223
mL, 2.028 mmol) followed by isobutyl chloroformate (0.266 mL, 2.028 mmol) dropwise.
The solution was then stirred for 30 min then filtered. The filtrate was added to
sodium borohydride (147 mg, 3.87 mmol) in water (10 mL), stirred for 5 min and diluted
with ethyl acetate (10 mL). The organic layer was separated and washed with brine
(2x10 mL), dried (Na
2SO
4) and evaporated under reduced pressure to afford
tert-butyl (5,5,5-trifluoro-1-hydroxypentan-2-yl)carbamate (400 mg, 1.555 mmol, 84% yield)
as a white solid which was taken to the next step without further purification.
1H NMR (400 MHz,
MeOD) δ 3.44-3.56 (m, 3H), 2.16-2.26 (m, 2H), 1.83-1.92 (m, 1H), 1.57-1.67 (m, 1H), 1.47
(s, 9H).

Part E. Tert-butyl 5,5,5-trifluoro-1-(6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)pentan-2-ylcarbamate
[0201] The reaction was carried out as in Ex. 2, Part D to yield product tert-butyl (5,5,5-trifluoro-1-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (160 mg, 0.237 mmol, 23% yield)
as a white solid. LC/MS (ESI)
m/
e 466.31 [(M+H)
+, calcd for C
23H
27F
3N
3O
4, 466.19]; LC/MS retention time (method D):
tR = 1.04 min.

Part F. 8-(2-amino-5,5,5-trifluoropentyloxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0202] To a solution of
tert-butyl (5,5,5-trifluoro-1-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (150 mg, 0.322 mmol) in diethyl
ether (10 mL) under nitrogen atmosphere, cooled to 0 °C was added 4M HCl in 1,4-dioxane
(0.098 mL, 0.392 mmol) slowly over a period of 5 min. The light yellow reaction mixture
was stirred at 0 °C for 5 min then warmed to room temperature and allowed to stir
for 12 h. The solvent was removed under reduced pressure. The residual yellow oil
was diluted with water (3 mL) and extracted with EtOAc (2x4 mL). The aqueous layer
was separated and treated with sat. Na
2CO
3 solution (3 mL). The resultant aqueous layer was extracted with EtOAc (3x5 mL). The
combined organic layer s were separated and washed with water (2x5 mL), brine (1x5
mL) and dried over sodium sulfate. The filtrate was evaporated under reduced pressure
and purified by SFC (CO
2 and 0.5% DEA in Methanol) to afford 8-((2-amino-5,5,5-trifluoropentyl)oxy)-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (102.8 mg, 0.278 mmol, 86% yield) as a white solid. LC/MS (ESI)
m/
e 366.2 [(M+H)
+, calcd for C
18H
19F
3N
3O
2 366.13]; LC/MS retention time (method C):
tR = 1.77 min; HPLC retention time (method A):
tR = 7.79 min; HPLC retention time (method B):
tR = 8.20 min.
1H NMR (400 MHz,
MeOD) δ 9.48 (d,
J = 0.80 Hz, 1H), 8.78 (d,
J = 5.60 Hz, 1H), 8.44 (d,
J = 8.80 Hz, 1H), 8.27 (d,
J = 5.60 Hz, 1H), 7.17 (d,
J = 2.40 Hz, 1H), 7.12 (dd,
J = 2.40, 8.80 Hz, 1H), 4.17-4.20 (m, 1H), 4.09 (dd,
J = 6.00, 9.40 Hz, 1H), 3.82 (s, 3H), 3.28-3.28 (m, 1H), 2.33-2.49 (m, 2H), 1.92-1.99
(m, 1H), 1.73-1.80 (m, 1H).
Example 16
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0203]

Part A: 2,4-dichloronicotinic acid
[0204] To a solution of 2,4-dichloropyridine (7 g, 47.3 mmol) in THF (70 mL) at - 78°C was
added a 2M solution of LDA in THF (28.4 mL, 56.8 mmol) and stirred for 30 min. The
reaction mixture was quenched with excess dry ice and stirred for 30 min at RT. After
neutralizing with 1.5N HCl, the reaction mixture was diluted with ethyl acetate (100
mL) and washed with brine (2x50 mL) and water (100 mL). The organic layer was separated,
dried over Na
2SO
4 and concentrated under reduced pressure to afford 2,4-dichloronicotinic acid (4.5
g, 23.44 mmol, 50% yield) as a brown solid.
1H NMR (400 MHz,
DMSO-d6) δ ppm 8.47 (d, 1H), 7.74 (d, 1H).

Part B: Methyl 2,4-dichloronicotinate
[0205] To a solution of 2,4-dichloronicotinic acid (500 mg, 2.60 mmol) in acetonitrile (10
mL) cooled to 0 °C was added DBU (0.981 mL, 6.51 mmol) followed by methyl iodide (0.814
mL, 13.0 mmol). The reaction mixture was stirred at RT overnight (14 h). After the
reaction completion, the solvent was removed under reduced pressure. The residue was
taken up in ethyl acetate (10 mL) and washed with water (1x5 mL), dried over Na
2SO
4, and concentrated under reduced pressure. The residue was purified by silica gel
column chromatography (EtOAc-hexane) to afford methyl 2,4-dichloronicotinate (260
mg, 1.262 mmol, 49% yield) as pale yellow oil. LC/MS, (ESI)
m/
z 206.1 [(M+H)
+, calcd for C
7H
6Cl
2NO
2 205.97]; LC/MS retention time (method D): t
R = 0.85 min.
1H NMR (300 MHz,
CD3OD) δ ppm 8.42 (d,
J= 5.4 Hz, 1H), 7.59 (d,
J= 5.4 Hz, 1H), 3.99 (s, 3H).

Part C: Methyl 4-chloro-2-methylnicotinate
[0206] A mixture of methyl 2,4-dichloronicotinate (2 g, 9.71 mmol), trimethylboroxine (1.462
g, 11.65 mmol), Cs
2CO
3 (6.33 g, 19.42 mmol) and PdCl
2(dppf) (0.710 g, 0.971 mmol) in 1,4-dioxane (30 mL) and water (2 mL) was purged with
nitrogen for 5 min and heated at 70 °C for 16 h. The reaction was concentrated under
reduced pressure and purified by silica gel column chromatography (EtOAc-hexane mixture)
to afford methyl 4-chloro-2-methylnicotinate (550 mg, 2.94 mmol, 31% yield) as a red
oil.
1H NMR (300 MHz,
CD3OD) δ ppm 8.44 (d,
J = 5.7 Hz, 1H), 7.43 (d,
J = 5.7 Hz , 1H), 3.98 (s, 3H), 2.54 (s, 3H).

Part D: Methyl 4-(4-chloro-2-fluorophenyl)-2-methylnicotinate
[0207] A mixture of methyl 4-chloro-2-methylnicotinate (4 g, 21.55 mmol), (4-chloro-2-fluorophenyl)boronic
acid (4.13 g, 23.71 mmol), tricyclohexylphosphine (1.813 g, 6.47 mmol), Pd(OAc)
2 (0.484 g, 2.155 mmol) and Cs
2CO
3 (14.04 g, 43.1 mmol) in DMA (15 mL) was purged with nitrogen for 5 min and heated
at 100 °C overnight (14 h). After cooling, the reaction mixture was filtered through
diatomaceous earth (Celite
®). DMA was removed under reduced pressure and the residue was diluted with ethyl acetate
(10 mL). The organic phase was concentrated under reduced pressure and purified by
silica gel column chromatography (EtOAc-hexane) to afford methyl 4-(4-chloro-2-fluorophenyl)-2-methylnicotinate
(1 g, 3.58 mmol, 17% yield) as a red oil. LC/MS, (ESI)
m/
z 280.1 [(M+H)
+, calcd for C
14H
12ClFNO
2 280.0]; LC/MS retention time (method D): t
R = 0.80 min.

Part E: 4-(4-chloro-2-fluorophenyl)-2-methylnicotinic acid
[0208] To a solution of methyl 4-(4-chloro-2-fluorophenyl)-2-methylnicotinate (40 mg, 0.143
mmol) in MeOH (2 mL) and water (3 mL) was added NaOH (11.44 mg, 0.286 mmol) and the
reaction mixture was stirred at RT for 14 h.. The reaction mixture was concentrated
under reduced pressure and acidified with 1.5N HCl the extracted with ethyl acetate
(5 mL). The organic layer was washed with saturated NaHCO
3 (2x10 mL) and water (10 mL); dried over Na
2SO
4 and concentrated under reduced pressure to afford crude 4-(4-chloro-2-fluorophenyl)-2-methylnicotinic
acid (30 mg, 0.113 mmol, 79% yield) as brown solid. This was taken into the next step
without further purification. LC/MS, (ESI)
m/
z 266.1 [(M+H)
+, calcd for C
13H
10ClFNO
2. 266.0]; LC/MS retention time (method D): t
R = 0.64 min.

Part F: 4-(4-chloro-2-fluorophenyl)-N,2-dimethylnicotinamide
[0209] To a solution of 4-(4-chloro-2-fluorophenyl)-2-methylnicotinic acid (180 mg, 0.678
mmol) in DCM (5 mL) and DMF (0.2 mL) at 0 °C, was added oxalyl chloride (0.178 mL,
2.033 mmol). The reaction mixture was stirred for 3 h at RT then diluted with DCM
(5 mL) and treated with a solution of methylamine hydrochloride (457 mg, 6.78 mmol)
in DCM (5 mL) cooled to 0°C. The mixture was stirred for another 1h at RT. The solution
was extracted with DCM (20 mL), washed with saturated NaHCO
3 (2x10 mL) and water (20 mL); dried over Na
2SO
4 and concentrated under reduced pressure to afford 4-(4-chloro-2-fluorophenyl)-N,2-dimethylnicotinamide
(50 mg, 0.179 mmol, 27% yield) as a brown gum. LC/MS, (ESI)
m/
z 279.2 [(M+H)
+, calcd for C
14H
13ClFN
2O 279.1]; LC/MS retention time (method D): t
R = 0.62 min.

Part G: 8-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0210] To a solution of 4-(4-chloro-2-fluorophenyl)-N,2-dimethylnicotinamide (40 mg, 0.144
mmol) in THF (3 mL) cooled to 0 °C was added NaH (10.33 mg, 0.431 mmol) and the reaction
mixture was stirred for 4 h. After the reaction completion , the reaction mixture
was quenched with ice water and the product was extracted with ethyl acetate (20 mL).
The organic layer was dried over Na
2SO
4 and concentrated under reduced pressure to afford 8-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6
H)-one (30 mg, 0.116 mmol, 81% yield) as an off-white solid. LC/MS, (ESI)
m/
z 259.2 [(M+H)
+, calcd for C
14H
12ClN
2O 259.1]; LC/MS retention time (Method D): t
R = 0.65 min.

Part H: (S)-tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0211] A mixture of 8-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (60 mg, 0.232 mmol), (
S)-
tert-butyl (1-hydroxy-4-methylpentan-2-yl)carbamate (101 mg, 0.464 mmol), Cs
2CO
3 (113 mg, 0.348 mmol), Pd(OAc)
2 (15.6 mg, 0.070 mmol) and 2-di-
t-butylphosphino-2',4',6'-tri-
i-propyl-1,1'-biphenyl (5.91 mg, 0.014 mmol) in toluene (5 mL) was purged with nitrogen
for 5 min and heated at 100 °C overnight (14 h). After cooling, the reaction mixture
was filtered through diatomaceous earth (Celite
®), concentrated under reduced pressure and dissolved in ethyl acetate (5 mL). The
organic layer was washed with brine (2x10 mL) and water (20 mL); dried over Na
2SO
4 and concentrated under reduced pressure to afford (
S)-
tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (55 mg crude) as a gummy
solid. The crude product was used in the next step without further purification. LC/MS,
(ESI)
m/
z 440.4 [(M+H)
+, calcd for C
25H
14N
3O
4, 440.2]; LC/MS retention time (method D): t
R = 0.89 min.

Part I: (S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0212] To a solution of (
S)-tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (30 mg, 0.068 mmol) in
MeOH (3 mL) at 0 °C was added HCl (4N in 1,4-dioxane, 3 mL, 12.00 mmol). The solution
was warmed to room temperature and stirred for 2 h. The reaction mixture was then
concentrated under reduced pressure and the residue dissolved in ethyl acetate (10
mL). The organic layer was washed with saturated NaHCO
3 (2x10 mL) and water (20 mL); dried over Na
2SO
4, and concentrated under reduced pressure. The residue was purified by preparative
TLC (DCM-MeOH mixture) to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (8 mg, 0.021 mmol, 31% yield) as a brown solid. LC/MS, (ESI)
m/
z 340.2 [(M+H)
+, calcd for C
20H
26N
3O
2, 340.2]; LC/MS retention time (method B): t
R = 1.27 min. HPLC retention time (method A):
tR = 8.30 and HPLC retention time (method B):
tR =8.97 min.
1H NMR (400 MHz,
CD3OD) δ ppm 8.53 (d,
J = 5.77 Hz, 1H), 8.33 (d,
J = 9.54 Hz, 1H), 8.08 (d,
J = 5.77 Hz, 1H), 7.00-7.06 (m, 2H), 4.21 (m, 1H), 4.02 (m, 1H), 3.73 (s, 3H), 3.47-3.52
(m, 1H), 3.06 (s, 3H), 1.82-1.93 (m, 1H), 1.67-1.76 (m, 2H), 1.26-1.56 (m, 6H).
Example 17
(S)-4-amino-8-(2-amino-4-methylpentyloxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0213]

Part A. tert-butyl (4-chloropyridin-2-yl)carbamate
[0214] To a solution of LHMDS (1M in THF, 17.11 mL, 17.11 mmol) in THF (5 mL) at -5 °C was
added a solution of 4-chloropyridin-2-amine (1 g, 7.78 mmol) in THF (5 mL) and the
mixture was stirred for 5 min. To this mixture was added a solution of Boc
2O (1.898 mL, 8.18 mmol) in THF (5 mL). The mixture was stirred at 0 °C for 2 h and
quenched by addition of aqueous NH
4Cl. The pH of the solution was adjusted to 6 by addition of 1.5N HCl and extracted
with ethyl acetate (3x15 mL). The combined organic extracts were washed with sodium
bicarbonate (15 mL), water (15 mL) and brine (15 mL). The combined organic extracts
were dried over sodium sulfate and concentrated under reduced pressure. The residue
was purified by silica gel column chromatography (ethyl acetate, petroleum ether gradient)
to yield
tert-butyl (4-chloropyridin-2-yl)carbamate (1.435 g, 6.28 mmol, 81% yield).
1H NMR.
1H NMR (400 MHz,
DMSO-d6) δ 10.10 (s, 1H), 8.23 (d,
J = 5.20 Hz, 1H), 7.88 (d,
J = 2.00 Hz, 1H), 7.15 (dd,
J = 2.00, 5.20 Hz, 1H), 1.48 (s, 9H).

Part B. tert-Butyl 4-chloro-3-formylpyridin-2-ylcarbamate
[0215] To a stirred solution of
tert-butyl (4-chloropyridin-2-yl)carbamate (1.00 g, 4.37 mmol) in THF (30 mL) cooled to
-78 °C was added
n-butyllithium (2.55 M in hexane, 4.1 mL, 10.06 mmol) dropwise. After complete addition
the solution was stirred at -78 °C for 1 h. DMF (1.591 mL, 20.55 mmol) was added dropwise
and the resultant solution stirred at -78 °C for an additional 1 h. The reaction mixture
was then quenched by addition of saturated aqueous ammonium chloride solution (20
mL) and extracted with ethyl acetate (2x25 mL). The combined organic extracts were
washed with brine (1x20 mL), dried over sodium sulfate and concentrated under reduced
pressure. The crude residue was purified via neutral alumina chromatography (ethyl
acetate/hexanes) to yield
tert-butyl (4-chloro-3-formylpyridin-2-yl)carbamate (530 mg, 2.06 mmol, 27% yield) as
a yellow solid.
1H NMR (400 MHz,
CDCl3) δ 10.73 (s, 1H), 10.55 (s, 1H), 8.52 (d,
J = 5.3 Hz, 1H), 7.06 (d,
J = 5.3 Hz, 1H), 1.56 (s, 9 H); LC/MS (ESI)
m/
e 255.2 [(M-H)
-, calcd for C
11H
12ClN
2O
3 255.1]. LC/MS retention time (method A) : t
R = 1.75 min.

Part C. tert-Butyl 4-(4-chloro-2-fluorophenyl)-3-formylpyridin-2-ylcarbamate
[0216] To a stirred suspension of
tert-butyl (4-bromo-3-formylpyridin-2-yl)carbamate (100 mg, 0.332 mmol), (4-chloro-2-fluorophenyl)boronic
acid (57.9 mg, 0.332 mmol) and cesium carbonate (216 mg, 0.664 mmol) in THF (50 mL)
and water (8 mL), was added Pd(PPh
3)
4 (19.19 mg, 0.017 mmol) and the reaction mixture was heated to 85 °C overnight (14
h). The reaction mixture was cooled to room temperature, diluted with water (30 mL)
and extracted with ethyl acetate (2x25 mL). The combined organic extracts were washed
with brine (1x25 mL), dried over sodium sulfate and concentrated under reduced pressure.
The crude residue was purified via silica gel chromatography (ethyl acetate/hexanes)
to afford
tert-butyl 4-(4-chloro-2-fluorophenyl)-3-formylpyridin-2-ylcarbamate (60 mg, 0.17 mmol,
35% yield). LC/MS (ESI)
m/
e 351.2 [(M+H)
+, calcd for C
17H
17ClFN
2O
3 351.1]. LC/MS retention time (method A):
tR = 2.07 min.

Part D. 4-((tert-butoxycarbonyl)amino)-8-chloro-6-methylbenzo[c][2,7] naphthyridin-6-ium
fluoride
[0217] To a stirred solution of
tert-butyl (4-(4-chloro-2-fluorophenyl)-3-formylpyridin-2-yl)carbamate (700 mg, 1.996
mmol) in ethanol (10 mL) at 0 °C was added methylamine (8M in EtOH) (620 mg, 2.49
mL, 19.96 mmol) and the reaction was stirred at rt for 5 h. After the consumption
of starting material, solvent was removed under reduced pressure. The residue was
washed with hexane (50 mL) and the solid so obtained was dried under vacuum to yield
the fluoride salt of 4-((
tert-butoxycarbonyl)amino)-8-chloro-6-methylbenzo[c][2,7] naphthyridin-6-ium fluoride (900
mg, 1.69 mmol, 84% yield) as a yellow solid. LC/MS (ESI)
m/
e 344.2 [(M)
+, calcd for C
18H
19ClN
3O
2 344.1]; LC/MS retention time (method C):
tR = 1.90 min.

Part E. 8-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-4-ylcarbamic acid
[0218] To a stirred solution of 4-((
tert-butoxycarbonyl)amino)-8-chloro-6-methylbenzo[c][2,7]naphthyridin-6-ium fluoride (0.35
g, 0.65 mmol) and NaOH (0.162 g, 4.06 mmol) in a mixture of DCM (10 mL) and water
(10 mL) was added KMnO
4 (0.642 g, 4.06 mmol) in portions at rt and the reaction was heated to 90 °C for 1
h. The solution was diluted with water (10 mL) and extracted with DCM (2x20 mL). The
combined organic layers were washed with water 50 mL, dried over sodium sulfate, and
concentrated under reduced pressure to yield (8-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-4-yl)carbamic
acid (305 mg, 0.422 mmol, 65% yield) as a yellow solid, which carried on without further
purification. LC/MS (ESI)
m/
e 304.1 [(M+H)
+, calcd for C
14H
11ClN
3O
3 304.04]; LC/MS retention time (Method D):
tR = 1.01 min.

Part F. 4-amino-8-chloro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0219] A solution of (8-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-4-yl)carbamic acid (300 mg, 0.415 mmol) in conc. HCl (15 mL, 494
mmol) was heated at 90 °C for 2 h. The pH of the reaction mixture was adjusted to
8 with saturated sodium bicarbonate solution and extracted with DCM (2x30 mL). The
combined organic layers were washed with brine (30 mL), dried over sodium sulfate,
and concentrated under reduced pressure. The residue was purified by prep. HPLC (0.1%
TFA in MeOH) to yield 4-amino-8-chloro-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (30 mg, 0.110 mmol, 27% yield) as a mono TFA salt. LC/MS (ESI)
m/
e 260.0 [(M+H)
+, calcd for C
13H
11ClN
3O 260.05]; LC/MS retention time (method B):
tR = 1.18 min; HPLC retention time (method A):
tR = 5.24 min; HPLC retention time (method B):
tR = 6.31 min; 400 MHz,
1H NMR (
DMSO-d6) δ 9.95 (s, 1H), 8.75 (s, 1H), 8.56 (d,
J= 8.80 Hz, 1H), 8.23 (d,
J= 6.80 Hz, 1H), 7.82 (dd,
J = 6.80, 7.20 Hz, 2H), 7.54 (dd,
J= 2.00, 8.80 Hz, 1H), 3.72 (s, 3H).

Part G. 8-chloro-4-(4-methoxybenzylamino)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0220] To a stirred solution of 4-amino-8-chloro-6-methylbenzo[
c][2,7]naphthyridin-5(6H)-one (30 mg, 0.059 mmol) in DMF (10 mL) at 0 °C was added
NaH (7.09 mg, 0.295 mmol) and the reaction was stirred for 5 min. To this mixture,
1-(chloromethyl)-4-methoxybenzene (0.026 mL, 0.191 mmol) was added and stirred at
rt for 16 h. The reaction was quenched by addition of ice and the reaction mixture
extracted with ethyl acetate (2x10 mL). The combined organic layers were washed with
water (25 mL), dried over sodium sulfate, and concentrated under reduced pressure
to yield 8-chloro-4-((4-methoxybenzyl)amino)-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (29 mg, 0.044 mmol, 75% yield). LC/MS (ESI)
m/
e 380.27 [(M+H)
+, calcd for C
21H
19ClN
3O
2 380.11]; LC/MS retention time (Method D):
tR = 0.86 min.

Part H. (S)-tert-butyl 1-(4-(4-methoxybenzylamino)-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0221] The reaction was carried out as in Ex. 2, Part D to afford crude product which was
purified by silica gel column using (ethyl acetate and hexane) to yield (
S)-
tert-butyl (1-((4-((4-methoxybenzyl)amino)-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
(0.29 g, 0.422 mmol, 61% yield) as a yellow oil. LC/MS (ESI)
m/
e 561.5 [(M+H)
+, calcd for C
32H
41N
4O
5 561.3]; LC/MS retention time (Method D):
tR = 1.03 min.

Part I. (S)-4-amino-8-(2-amino-4-methylpentyloxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0222] To a stirred solution of (
S)-
tert-butyl (1-((4-((4-methoxybenzyl)amino)-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
(100 mg, 0.145 mmol) in DCM (10 mL) at rt was added TFA (4 mL, 51.9 mmol) dropwise
and the reaction was heated at 45 °C for 12 h. After the completion of reaction, the
volatile organics were evaporated under reduced pressure and the residue obtained
was purified by prep. HPLC (0.1% TFA in water/acetonitrile as mobile phase) to yield
(
S)-4-amino-8-((2-amino-4-methylpentyl)oxy)-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (16 mg, 0.046 mmol, 32% yield) as a mono TFA salt as an off white solid. LC/MS
(ESI)
m/
e 341.2 [(M+H)
+, calcd for C
19H
25N
4O
2 341.2]; LC/MS retention time (method B):
tR = 1.08 min; HPLC retention time (method A):
tR = 8.02 min; HPLC retention time (method B):
tR = 8.40 min;
1H NMR (400 MHz,
MeOD) δ 8.44 (d,
J = 8.80 Hz, 1H), 8.00 (d,
J = 7.20 Hz, 1H), 7.71 (d,
J = 7.20 Hz, 1H), 7.24 (d,
J = 2.40 Hz, 1H), 7.21-7.22 (m, 1H), 4.51 (dd,
J = 3.20, 10.80 Hz, 1H), 4.34 (dd,
J = 6.40, 10.40 Hz, 1H), 3.84 (s, 3H), 3.78-3.82 (m, 1H), 1.65-1.89 (m, 3H), 1.08 (d,
J = 4.40 Hz, 3H), 1.06 (d,
J = 4.40 Hz, 3H).
Example 18
(S)-N-(8-(2-amino-4-methylpentyloxy)-6-methyl-5-oxo-5,6 dihydrobenzo[c][2,7]naphthyridin-2-yl)acetamide
[0223]

Part A. 4-chloropyridin-2-amine
[0224] To a stirred solution of 4-chloropyridin-2-amine (8 g, 62.2 mmol) in acetonitrile
(600 mL) at rt was added
N-bromosuccinimide (11.08 g, 62.2 mmol) in portions and the reaction was stirred for
14 h. The reaction mixture was concentrated under reduced pressure. The residue was
diluted with water (50 mL) and extracted with EtOAc (3x50 mL). The combined organic
layers were washed with water (100 mL), brine (100 mL) and dried over sodium sulfate.
The organics were concentrated under reduced pressure to afford 5-bromo-4-chloropyridin-2-amine
as yellow solid (13 g, 99%) that was used as is without further purification. LC/MS
(ESI)
m/
e 207.0 [(M+H)
+, calcd for C
5H
5BrClN
2 206.9]; LC/MS retention time (method B):
tR = 0.8 min.

Part B. N-(5-bromo-4-chloropyridin-2-yl)acetamide
[0225] To a stirred solution of 5-bromo-4-chloropyridin-2-amine (11.6 g, 55.9 mmol) in pyridine
(100 mL) at 0 °C was added acetyl chloride (3.98 mL, 55.9 mmol) and the reaction was
stirred at rt for 3 h. The reaction mixture was quenched with cold water and concentrated
under reduced pressure. The residue was diluted with water (50 mL) and extracted with
EtOAc (3x50 mL). The combined organic layers were washed with water (100 mL), brine
(100 mL) and dried over sodium sulfate. The organics were concentrated under reduced
pressure to afford
N-(5-bromo-4-chloropyridin-2-yl)acetamide (14.6 g, 55.9 mmol, 100% yield) as a white
solid that was carried on without further purification. LC/MS (ESI)
m/
e 249 [(M+H)
+, calcd for C
7H
7BrClN
2O 248.9], LC/MS retention time (method B):
tR = 1.64 min;
1H NMR (400 MHz,
DMSO-d6) δ 10.87 (s, 1H), 8.58 (s, 1H), 8.33 (s, 1H), 2.11 (s, 3H).

Part C. N-(4-chloro-5-vinylpyridin-2-yl)acetamide
[0226] To a stirred solution of
N-(5-bromo-4-chloropyridin-2-yl)acetamide (7 g, 28.1 mmol), 2,4,6-trivinyl-1,3,5,2,4,6-trioxatriborinane
complex with pyridine (1:1) (8.78 g, 36.5 mmol), sodium carbonate (5.95 g, 56.1 mmol)
solution in 7 mL of water and tetrakis(triphenylphosphine)palladium (0.973 g, 0.842
mmol) in a mixture of Toluene (50 mL) and Ethanol (8 mL), nitrogen gas was bubbled
for 5 min. The reaction mixture was heated at 85 °C for 14 hours. After the completion,
the reaction was diluted with EtOAc (50 mL), filtered through diatomaceous earth (Celite
®). The filtrate was diluted with water and the organic layer was separated, washed
with brine solution, dried over sodium sulfate. The organics were concentrated under
reduced pressure and residue so obtained was purified by comb flash column 120 g using
hexane/ethyl acetate. Product eluted at 30% EtOAc in hexane and required fractions
were concentrated to yield
N-(4-chloro-5-vinylpyridin-2-yl)acetamide (5.92 g, 27.7 mmol, 99% yield) as yellow
solid. LC/MS (ESI)
m/
e 197.2 [(M+H)
+, calcd for C
9H
10ClN
2O 197.04] LC/MS retention time (method A):
tR = 1.50 min;
1H NMR (400 MHz,
DMSO-d6) δ 10.79 (s, 1H), 8.64 (s, 1H), 8.18 (d,
J= 6.40 Hz, 1H), 6.88 (dd,
J = 11.20, 17.60 Hz, 1H), 5.99 (dd,
J = 0.80, 17.60 Hz, 1H), 5.47 (dd,
J = 0.80, 11.40 Hz, 1H), 2.12 (s, 3H).

Part D. N-(4-chloro-5-formylpyridin-2-yl)acetamide
[0227] To a stirred solution of N-(4-chloro-5-vinylpyridin-2-yl)acetamide (6 g, 30.5 mmol)
and 2,6-lutidine (7.11 mL, 61.0 mmol) in a mixture of 1,4-dioxane (110 mL) and water
(25 mL) at 0 °C was added osmium tetroxide (2.5% in 2-methyl-2-propanol, 9.58 mL,
30.5 mmol) followed by the addition of sodium periodate (19.58 g, 92 mmol) and the
reaction was stirred for 4 h. The reaction mixture was diluted with water and extracted
with EtOAc (2x100 mL). The combined organic layers were washed with brine solution,
dried over sodium sulfate, concentrated under reduced pressure and residue so obtained
was purified by comb flash column 120 g silica column using hexane/EtOAc as eluant.
The desired product was isolated at 30% EtOAc in hexane. The required fractions were
concentrated under reduced pressure to yield N-(4-chloro-5-formylpyridin-2-yl)acetamide
as a off-white solid (5.8 g, 28.1 mmol, 92% yield). LC/MS (ESI)
m/
e 197.0 [(M)
-, calcd for C
8H
6ClN
2O
2 197.04] LC/MS retention time (method A):
tR = 1.21 min;
1H NMR (400 MHz,
DMSO-d6) δ 11.20 (s, 1H), 10.18 (s, 1H), 8.76 (s, 1H), 8.27 (s, 1H), 2.16 (s, 3H).

Part E. N-(4-(4-chloro-2-fluorophenyl)-5-formylpyridin-2-yl)acetamide
[0228] To a stirred solution ofN-(4-chloro-5-formylpyridin-2-yl)acetamide (3g, 15.11 mmol),
(4-chloro-2-fluorophenyl)boronic acid (2.63 g, 15.11 mmol), cesium carbonate (9.84
g, 30.2 mmol) in a mixture of water (8 mL) and THF (25 mL) was added tetrakis(triphenylphosphine)palladium
(19.19 mg, 0.017 mmol) and the reaction was heated to 85 °C overnight (14 h). The
reaction mixture was diluted with water (25 mL) and extracted with EtOAc (2x25 mL).
The combined organic layers were washed with water (25 mL), brine (25 mL), dried over
sodium sulfate, and concentrated under reduced pressure. The residue was purified
by silica gel chromatography (hexane/EtOAc as eluant), yielding
N-(4-(4-chloro-2-fluorophenyl)-5-formylpyridin-2-yl)acetamide as an off-white solid
(2.8 g, 9.01 mmol, 60% yield). LC/MS (ESI)
m/
e 291.0 [(M)
-, calcd for C
14H
9ClFN
2O
2 291.0], LC/MS retention time (method A):
tR = 1.69 min;
1H NMR (400 MHz,
DMSO-d6) δ 11.14 (s, 1H), 9.84 (d,
J = Hz, 1H), 8.88 (s, 1H), 8.13 (s, 1H), 7.61 (dd,
J = 2.00, 10.00 Hz, 1H), 7.46-7.48 (m, 2H), 2.11 (s, 3H).

Part F. 2-Acetamido-8-chloro-6-methylbenzo[c][2,7]naphthyridin-6-ium fluoride
[0229] To a stirred solution of
N-(4-(4-chloro-2-fluorophenyl)-5-formylpyridin-2-yl)acetamide (0.39 g, 1.332 mmol)
and 4 Å molecular sieves (50 mg) in dichloromethane (35 mL) at 0 °C was added methyl
amine (8M in EtOH, 0.041 g, 0.166 mL,1.332 mmol) dropwise and the reaction was stirred
at rt overnight (12 h). The reaction mixture was diluted with DCM (40 mL) and filtered
through a bed of diatomaceous earth (Celite
®). The filtrate was concentrated under reduced pressure to afford 2-acetamido-8-chloro-6-methylbenzo[c][2,7]naphthyridin-6-ium
fluoride (450 mg, 1.24 mmol, 93% yield) as a yellow solid that was used in the next
step without purification. LC/MS (ESI)
m/
e 286.1 [(M)
+, calcd for C
15H
13ClN
3O 286.1]; LC/MS retention time (Method D):
tR = 0.71 min.

Part G. N-(8-chloro-6-methyl-5,6-dihydrobenzo[c][2,7]naphthyridin-2-yl)acetamide
[0230] To a stirred solution of 2-acetamido-8-chloro-6-methylbenzo[c][2,7]naphthyridin-6-ium
fluoride (2.1 g, 2.47 mmol) in a mixture of THF (20 mL) and MeOH (5 mL) at 0 °C was
added NaBH
4 (0.199 g, 5.27 mmol) in three portions and the reaction was stirred at rt for 45
min. The volatile organics were removed under reduced pressure; saturated ammonium
chloride solution (30 mL) was added and the solution extracted with ethyl acetate
(2x30 mL). The combined organic layers were washed with brine (25 mL), dried over
sodium sulfate, and concentrated under reduced pressure. The residue was purified
by silica gel column chromatography (hexane/ ethyl acetate) to afford
N-(8-chloro-6-methyl-5,6-dihydrobenzo[
c][2,7]naphthyridin-2-yl)acetamide (0.71 g, 2.29 mmol, 93 % yield) as a yellow solid.
LC/MS (ESI)
m/
e 288.2 [(M+H)
+, calcd for C
15H
15ClN
3O 288.1]; LC/MS retention time (method C);
tR = 1.87 min; HPLC retention time (method A):
tR = 12.76 min; HPLC retention time (method B):
tR = 13.07 min;
1H NMR (400 MHz,
DMSO-d6) δ 10.46 (s, 1H), 8.36 (s, 1H), 8.16 (d,
J = 0.40 Hz, 1H), 7.63 (d,
J = 8.40 Hz, 1H), 6.88 (dd,
J = 2.00, 8.00 Hz, 1H), 6.82 (d,
J = 2.00 Hz, 1H), 4.26 (s, 2H), 2.89 (s, 3H), 2.11 (s, 3H).

Part H. N-(8-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-2-yl)acetamide
[0231] To a stirred solution of
N-(8-chloro-6-methyl-5,6-dihydrobenzo[
c][2,7]naphthyridin-2-yl)acetamide (0.6 g, 1.199 mmol) in DCM (20 mL) at rt was added
barium manganate (1.536 g, 5.99 mmol) in three portions and the reaction was heated
at 45 °C for 60 h. After the completion of reaction, the reaction mixture was diluted
with DCM (70 mL) and passed through diatomaceous earth (Celite
®). The filtrate was concentrated under reduced pressure. The residue was purified
by silica gel column chromatography (DCM/ MeOH as an eluant) to yield
N-(8-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-2-yl)acetamide (0.4 g, 1.071 mmol, 89% yield) as an off white solid.
LC/MS (ESI)
m/
e 302.1 [(M+H)
+, calcd for C
15H
13ClN
3O
2 302.1]; LC/MS retention time (method C):
tR = 1.88 min; HPLC retention time (method A);
tR = 8.82 min; HPLC retention time (method B):
tR = 7.99 min;
1H NMR (400 MHz,
DMSO-d6) δ 11.01 (s, 1H), 9.24 (s, 1H), 8.92 (s, 1H), 8.26 (d,
J = 8.80 Hz, 1H), 7.69 (d,
J = 2.00 Hz, 1H), 7.48 (dd,
J = 2.00, 8.80 Hz, 1H), 3.68 (s, 3H), 2.20 (s, 3H).

Part 1. (S)-tert-butyl 1-(2-acetamido-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0232] The reaction was carried out as in Ex. 2, Part D to afford crude (
S)
-tert-butyl 1-(2-acetamido-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate (160 mg, 0.33 mmol, 20.5%
pure by LC/MS) as a brown oil. This was taken to the next step without purification.
LC/MS (ESI)
m/
e 483.34 [(M+H)
+, calcd for C
26H
35N
4O5 483.25]; LC/MS retention time (Method E):
tR = 1.13 min.

Part J. (S)-N-(8-(2-amino-4-methylpentyloxy)-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-2-yl)acetamide
[0233] To a stirred solution of (
S)-
tert-butyl (1-((2-acetamido-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (140 mg, 0.059 mmol) in
CH
2Cl
2 (15 mL) at 0 °C was added TFA (1.2 mL, 15.58 mmol) and the reaction mixture was stirred
at RT for 40 min. After the completion of reaction, the volatile organics were evaporated
under reduced pressure and the residue was purified by preparative HPLC (0.1% TFA
in water/Acetonitrile) to yield (
S)-
N-(8-((2-amino-4-methylpentyl)oxy)-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-2-yl)acetamide (2 mg, 3.93 µmol, 6.6% yield) as a mono TFA salt.
LC/MS (ESI)
m/
e 383.2 [(M+H)
+, calcd for C
21H
27N
4O
3 383.2]; LC/MS retention time (method C):
tR = 1.80 min; HPLC retention time (method A):
tR = 5.14 min; HPLC retention time (method B):
tR = 5.62 min;
1H NMR (400 MHz,
CD3OD) δ 9.28 (s, 1H), 8.93 (s, 1H), 8.35 (d,
J = 8.80 Hz, 1H), 7.17 (s, 1H), 7.15 (d,
J = 2.00 Hz, 1H), 4.46 (d,
J = 8.80 Hz, 1H), 4.28 (dd,
J = 6.40, 10.80 Hz, 1H), 3.76-3.79 (m, 4H), 2.29 (s, 3H), 1.65-1.88 (m, 3H), 1.08 (d,
J = 4.40 Hz, 3H), 1.07 (d,
J = 4.40 Hz, 3H).
Example 19
(R)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0234]

Part A. (R)-tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0235] The title compound was prepared as described in Example 16 using (
R)-
tert-butyl (1-hydroxy-4-methylpentan-2-yl)carbamate in part H to afford (
R)-
tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (620 mg, 0.564 mmol, 49
% yield) as a yellow solid. LC/MS, (ESI)
m/
z 440.3 [(M+H)
+, calcd for C
25H
34N
3O
4 440.3].

Part B. (R)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0236] An ambient temperature solution of (
R)-
tert-t-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (102 mg, 0.232 mmol) in
dichloromethane (1 mL) was treated with HCl (1.160 mL, 4.64 mmol) and stirred for
1 h. The resulting mixture was concentrated to an oil and purified by reverse phase
high performance liquid chromatography (Phenomenex Luna C18 30x100mm 10 micron; water/methanol/0.1
% TFA gradient elution). Fractions containing product were neutralized with saturated
aqueous sodium bicarbonate and concentrated under reduced pressure. The residue was
partitioned between ethyl acetate and brine and the layers were separated. The aqueous
was extracted twice more with ethyl acetate and the pooled organics were washed once
with brine, dried over magnesium sulfate, filtered, and concentrated to afford (R)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (11.5 mg, 0.033 mmol, 14 % yield) as a milky oil. LC/MS, (ESI)
m/
z 340.2 [(M+H)
+, calcd for C
20H
26N
3O
2 340.2]; HPLC retention time (method C):
tR = 13.02 min; HPLC retention time (method D):
tR = 13.05 min;
1H NMR (500MHz, METHANOL-d
4) δ 8.68 - 8.63 (m, 2H), 8.58 (d,
J=9.0 Hz, 1H), 7.22 (dd,
J=9.0, 2.3 Hz, 1H), 7.20 (d,
J=2.3 Hz, 1H), 4.52 (dd,
J=10. 5, 3.3 Hz, 1H), 4.34 (dd,
J=10.7, 6.6 Hz, 1H), 3.82 (s, 3H), 3.80 - 3.75 (m, 1H), 3.25 (s, 3H), 1.91 - 1.81 (m,
1H), 1.80-1.73 (m, 1H), 1.72 - 1.64 (m, 1H), 1.07 (d,
J=5.8 Hz, 3H), 1.06 (d,
J=5.8 Hz, 3H).
Example 20
(R)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0237]

Part A. (R)-tert-butyl (1-((9-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0238] A mixture of (
R)-
tert-t-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
(248 mg, 0.564 mmol) prepared as described in Example 19, Part A, NCS (151 mg, 1.128
mmol), and acetonitrile (5 mL) was heated at 90 °C for 1 h and then stirred at room
temperature overnight. The crude material was concentrated under reduced pressure
to afford (
R)-
tert-t-butyl (1-((9-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
(15 mg, 0.032 mmol, 6 % crude yield). The mixture was carried on without further purification.
LC/MS, (ESI)
m/
z 474.2 [(M+H)
+, calcd for C
25H
33ClN
3O
4 474.2].

Part B. (R)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0239] An ambient temperature solution of (
R)-
tert-t-butyl (1-((9-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (15 mg, 0.032 mmol) in
dichloromethane (0.5 mL) was treated with HCl (4M in 1,4-dioxane) (0.396 mL, 1.58
mmol) and stirred for 1 h. The resulting mixture was concentrated and the residue
was purified by reverse phase high performance liquid chromatography (Phenomenex Luna
C18 30 x 100 mm 10 micron; water/acetonitrile/10 mM ammonium acetate gradient elution).
Fractions containing product were concentrated under reduced pressure to afford (
R)-
tert-butyl (1-((9-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate one (9.0 mg, 0.023 mmol,
73 % yield) as a white solid. LC/MS, (ESI)
m/
z 373.2 [(M+H)
+, calcd for C
20H
25ClN
3O
2 373.2]; HPLC retention time (method C):
tR = 14.21 min; HPLC retention time (method D):
tR = 14.30 min;
1H NMR (400MHz, CHLOROFORM-d) δ 8.70 (d,
J=5.8 Hz, 1H), 8.21 (s, 1H), 7.79 (d,
J=5.8 Hz, 1H), 6.83 (s, 1H), 4.18 (dd,
J=8.8, 3.8 Hz, 1H), 4.04 - 3.97 (m, 1H), 3.76 (s, 3H), 3.48 (qd,
J=6.9, 3.5 Hz, 1H), 3.17 (s, 3H), 1.84 (dquin,
J=13.7, 6.7 Hz, 1H), 1.49 (t,
J=7.0 Hz, 2H), 1.03 (d,
J=6.5 Hz, 3H), 1.01 (d,
J=6.5 Hz, 3H).
Example 21
(S)-8-(2-amino-3-cyclopropylpropoxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0240]

Part A: (S)-tert-butyl (1-cyclopropyl-3-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate
[0241] The title compound was prepared as described in Example 16 using (
S)-
tert-butyl (1-cyclopropyl-3-hydroxypropan-2-yl)carbamate (0.287 g, 1.334 mmol) in Part
H to afford (
S)-
tert-butyl (1-cyclopropyl-3-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate (230 mg, 0.526 mmol, 59 % yield)
as a colorless oil. LC/MS, (ESI)
m/
z 438.3 [(M+H)
+, calcd for C
25H
12N
3O
4 438.2];
1H NMR (400MHz, CHLOROFORM-d) δ 8.61 (d,
J=5.5 Hz, 1H), 8.09 (d,
J=8.8 Hz, 1H), 7.77 (d,
J=5.5 Hz, 1H), 6.96 - 6.79 (m, 2H), 4.92 (br. s., 1H), 4.35 - 3.98 (m, 3H), 3.70 (s,
3H), 3.13 (s, 3H), 1.63 (t,
J=6.9 Hz, 2H), 1.47 (s, 9H), 0.83 - 0.70 (m, 1H), 0.61 - 0.42 (m, 2H), 0.21 - 0.04
(m, 2H).

Part B: (S)-8-(2-amino-3-cyclopropylpropoxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0242] An ambient temperature suspension of (
S)-
tert-butyl(1-cyclopropyl-3-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate (50 mg, 0.114 mmol) (prepared as
described in Example 16 using (
S)-
tert-butyl (1-cyclopropyl-3-hydroxypropan-2-yl)carbamate (0.287 g, 1.334 mmol) in Part
H) in diethyl ether (1 mL) was treated with HCl (4M in 1,4-dioxane) (0.571 mL, 2.286
mmol) and stirred for 1 h. The resulting mixture was concentrated under reduced pressure
to a yellow solid. The crude material was purified by reverse phase high performance
liquid chromatography (Phenomenex Luna C18 30 x 100 mm 10 micron; water/methanol/TFA
gradient elution). Fractions containing product were concentrated under reduced pressure.
The resulting residue was partitioned between saturated aqueous sodium bicarbonate
and ethyl acetate. The layers were separated and the aqueous was extracted twice more
with ethyl acetate. The pooled organics were washed once with brine, dried over magnesium
sulfate, filtered, and concentrated to afford (
S)-8-(2-amino-3-cyclopropylpropoxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (9.0 mg, 0.025 mmol, 22 % yield for the final step) as a white solid. LC/MS,
(ESI)
m/
z 338.2 [(M+H)
+, calcd for C
20H
24N
3O
2 338.2]; HPLC retention time (method C):
tR = 13.05 min; HPLC retention time (method D):
tR = 13.88 min;
1H NMR (400MHz, CHLOROFORM-d) δ 8.65 (d,
J=5.8 Hz, 1H), 8.16 (d,
J=8.8 Hz, 1H), 7.83 (d,
J=5.5 Hz, 1H), 6.92 (dd,
J=8.9, 2.4 Hz, 1H), 6.87 (d,
J=2.3 Hz, 1H), 4.15 (dd,
J=8.9, 3.9 Hz, 1H), 3.97 (dd,
J=8.8, 7.0 Hz, 1H), 3.75 (s, 3H), 3.48 - 3.35 (m, 1H), 3.17 (s, 3H), 1.59 - 1.42 (m,
2H), 0.87 - 0.74 (m, 1H), 0.64 - 0.47 (m, 2H), 0.25 - 0.17 (m, 1H), 0.16 - 0.10 (m,
1H).
Example 22
(S)-8-(2-amino-3-cyclobutylpropoxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0243]

Part A: (S)-tert-butyl (1-cyclobutyl-3-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate
[0244] The title compound was prepared as described in Example 16 using (
S)-
tert-butyl (1-cyclobutyl-3-hydroxypropan-2-yl)carbamate (0.359 g, 1.566 mmol)in Part H
to afford (
S)
-tert-butyl (1-cyclobutyl-3-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate (400 mg, 0.886 mmol, 85 % yield)
as a colorless oil. LC/MS, (ESI)
m/
z 452.3 [(M+H)
+, calcd for C
26H
14N
3O
4 452.3];
1H NMR (400MHz, CHLOROFORM-d) δ 8.62 (d,
J=5.8 Hz, 1H), 8.11 (d,
J=8.8 Hz, 1H), 7.79 (d,
J=5.5 Hz, 1H), 6.94 - 6.79 (m, 2H), 4.76 (d,
J=7.5 Hz, 1H), 4.07 (d,
J=3.5 Hz, 2H), 3.93 (br. s., 1H), 3.71 (s, 3H), 3.14 (s, 3H), 2.55 - 2.35 (m, 1H),
2.15 - 2.05 (m, 2H), 1.97 - 1.59 (m, 7H), 1.47 (s, 9H).

Part B: (S)-8-(2-amino-3-cyclobutylpropoxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0245] An ambient temperature suspension of (
S)-
tert-butyl (1-cyclobutyl-3-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate (70 mg, 0.155 mmol) in diethyl ether
(1 mL) was treated with HCl (4M in 1,4-dioxane) (0.775 mL, 3.10 mmol) and stirred
for 1 h. The resulting mixture was concentrated under reduced pressure to a yellow
solid. The crude material was purified by reverse phase high performance liquid chromatography
(Phenomenex Luna C18 30 x 100 mm 10 micron; water/methanol/TFA gradient elution).
Fractions containing product were concentrated under reduced pressure. The resulting
residue was partitioned between saturated aqueous sodium bicarbonate and ethyl acetate.
The layers were separated and the aqueous was extracted twice more with ethyl acetate.
The pooled organics were washed once with brine, dried over magnesium sulfate, filtered,
and concentrated under reduced pressure to afford (
S)-8-(2-amino-3-cyclobutylpropoxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (17 mg, 0.046 mmol, 30 % yield) as a white solid. LC/MS, (ESI)
m/
z 352.3 [(M+H)
+, calcd for C
21H
26N
3O
2 352.2]; HPLC retention time (method C):
tR = 14.15 min; HPLC retention time (method D):
tR = 14.78 min;
1H NMR (400MHz, CHLOROFORM-d) δ 8.64 (d,
J=5.8 Hz, 1H), 8.15 (d,
J=9.0 Hz, 1H), 7.82 (d,
J=5.8 Hz, 1H), 6.89 (dd,
J=8.9, 2.4 Hz, 1H), 6.84 (d,
J=2.3 Hz, 1H), 4.04 (dd,
J=8.9, 3.9 Hz, 1H), 3.86 (dd,
J=8.8, 7.5 Hz, 1H), 3.73 (s, 3H), 3.23 (tdd,
J=7.5, 5.5, 3.8 Hz, 1H), 3.16 (s, 3H), 2.60 - 2.43 (m, 1H), 2.21 - 2.08 (m, 2H), 2.01
- 1.81 (m, 2H), 1.80 - 1.55 (m, 4H).
Example 23
(S)-8-(2-amino-3-cyclopropylpropoxy)-9-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0246]

[0247] The title compound was prepared as described in Example 20 to afford (
S)-8-(2-amino-3-cyclopropylpropoxy)-9-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (12.5 mg, 0.030 mmol, 24 % yield for the final step) as a pale yellow solid.
LC/MS, (ESI)
m/
z 372.2 [(M+H)
+, calcd for C
20H
23ClN
3O
2 372.2]; HPLC retention time (method C):
tR = 14.16 min; HPLC retention time (method D):
tR = 15.03 min;
1H NMR (400MHz, CHLOROFORM-d) δ 8.66 (d,
J=5.5 Hz, 1H), 8.17 (s, 1H), 7.74 (d,
J=5.8 Hz, 1H), 6.81 (s, 1H), 4.22 (dd,
J=8.7, 3.9 Hz, 1H), 4.05 (dd,
J=8.5, 7.0 Hz, 1H), 3.73 (s, 3H), 3.49 (qd,
J=6.8, 4.0 Hz, 1H), 3.20 - 3.12 (m, 3H), 1.63 - 1.46 (m, 2H), 0.89 - 0.75 (m, 1H),
0.67 - 0.45 (m, 2H), 0.25 - 0.18 (m, 1H), 0.17 - 0.10 (m, 1H).
Example 24
(S)-8-(2-amino-3-cyclobutylpropoxy)-9-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0248]

[0249] The title compound was prepared as described in Example 20 to afford (
S)-8-(2-amino-3-cyclobutylpropoxy)-9-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (10.5 mg, 0.027 mmol, 24 % yield for the final step) as a colorless solid. LC/MS,
(ESI)
m/
z 386.2 [(M+H)
+, calcd for C
21H
25ClN
3O
2 386.2]; HPLC retention time (method C):
tR = 14.92 min; HPLC retention time (method D):
tR = 15.61 min;
1H NMR (400MHz, CHLOROFORM-d) δ 8.68 (d,
J=5.5 Hz, 1H), 8.20 (s, 1H), 7.77 (d,
J=5.8 Hz, 1H), 6.81 (s, 1H), 4.14 (dd,
J=8.7, 3.9 Hz, 1H), 4.01 - 3.91 (m, 1H), 3.75 (s, 3H), 3.34 (d,
J=4.5 Hz, 1H), 3.17 (s, 3H), 2.62 - 2.44 (m, 1H), 2.22 - 2.06 (m, 2H), 2.01 - 1.82
(m, 2H), 1.82 - 1.63 (m, 4H).
Example 25
(S)-8-(2-amino-3-cyclopropylpropoxy)-4,6,9-trimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0250]

Part A: (S)-tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-3-cyclopropylpropan-2-yl)carbamate
[0251] A mixture of (
S)
-tert-butyl (1-cyclopropyl-3-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate (100 mg, 0.229 mmol) prepared as
described in Example 21, Part A in acetonitrile (5 mL) was heated to 90 °C for 1 h
resulting in a homogeneous orange solution. The solution was treated with saturated
aqueous sodium bicarbonate and concentrated under reduced pressure. The residue was
partitioned between brine and ethyl acetate and the layers were separated. The aqueous
layer was extracted twice more with ethyl acetate and the pooled organics were washed
once with brine, dried over magnesium sulfate, filtered, and concentrated to a solid.
The solid was purified via silica gel chromatography (1% ammonia in methanol/dichloromethane)
to afford (
S)
-tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-3-cyclopropylpropan-2-yl)carbamate (53 mg, 0.103 mmol,
45 % yield) as a colorless oil which solidified upon standing. LC/MS, (ESI)
m/
z 516.2, 518.2 Br pattern [(M+H)
+, calcd for C
25H
31BrN
3O
4 516.2].

Part B: (S)-tert-t-butyl (1-cyclopropyl-3-((4,6,9-trimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate
[0252] An ambient temperature mixture of (
S)-
tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-3-cyclopropylpropan-2-yl)carbamate (51 mg, 0.099 mmol),
trimethylboroxine (0.015 mL, 0.109 mmol), PdCl
2(dppf)-CH
2Cl
2Adduct (8.06 mg, 9.88 µmol), cesium carbonate (64.4 mg, 0.198 mmol), 1,4-dioxane (1
mL), and water (0.33 mL) was charged to a pressure rated vial and purged with a stream
of nitrogen for 10 minutes. The vial was sealed and stirred under nitrogen at 75 °C
for 12 h. The resulting mixture was cooled to room temperature and vacuum filtered.
The filtrate was concentrated under reduced pressure and the residue was partitioned
between ethyl acetate and brine. The layers were separated and the aqueous layer was
extracted twice more with ethyl acetate. The pooled organics were dried over magnesium
sulfate, filtered, and concentrated to an oil. The oil was purified via silica gel
chromatography (1% 2M ammonia in methanol/dichloromethane) to afford (
S)-
tert-butyl(1-cyclopropyl-3-((4,6,9-trimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate (41 mg, 0.091 mmol, 92 % yield)
as a colorless oil. LC/MS, (ESI)
m/
z 452.3 [(M+H)
+, calcd for C
26H
34N
3O
4 452.3];
1H NMR (400MHz, CHLOROFORM-d) δ 8.59 (d,
J=5.8 Hz, 1H), 7.90 (s, 1H), 7.78 (d,
J=5.8 Hz, 1H), 6.74 (s, 1H), 4.91 (d,
J=7.3 Hz, 1H), 4.35 - 4.04 (m, 3H), 3.71 (s, 3H), 3.14 (s, 3H), 2.31 (s, 3H), 1.72-1.59
(m, 2H), 1.48 (s, 9H), 0.86 - 0.70 (m, 1H), 0.60 - 0.44 (m, 2H), 0.21 - 0.00 (m, 2H).

Part C: (S)-8-(2-amino-3-cyclopropylpropoxy)-4,6,9-trimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0253] An ambient temperature solution of (
S)-
tert-butyl(1-cyclopropyl-3-((4,6,9-trimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate (41 mg, 0.091 mmol) in methanol
(0.5 mL) was treated with HCl (4M in 1,4-dioxane) (0.454 mL, 1.816 mmol) and stirred
for 1 h. The resulting mixture was concentrated under reduced pressure to yellow solid.
The crude material was purified by reverse phase high performance liquid chromatography
(Phenomenex Luna C18 30x100 mm 10 micron; water/methanol/TFA gradient elution). Product
containing fractions were neutralized with saturated aqueous sodium bicarbonate and
concentrated under reduced pressure. The resulting residue was partitioned between
water and ethyl acetate and the layers were separated. The aqueous was extracted twice
more with ethyl acetate and the pooled organics were dried over magnesium sulfate,
filtered, and concentrated to afford (
S)-8-(2-amino-3-cyclopropylpropoxy)-4,6,9-trimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (10.7 mg, 0.028 mmol, 93 % yield) as a colorless solid. LC/MS, (ESI)
m/
z 352.2 [(M+H)
+, calcd for C
21H
26N
3O
2 352.2]; HPLC retention time (method C):
tR = 13.71 min; HPLC retention time (method D):
tR = 14.29 min;
1H NMR (400MHz, CHLOROFORM-d) δ 8.63 (d,
J=5.5 Hz, 1H), 7.98 (s, 1H), 7.84 (d,
J=5.8 Hz, 1H), 6.74 (s, 1H), 4.15 (dd,
J=8.8, 4.0 Hz, 1H), 4.00 (dd,
J=8.7, 6.9 Hz, 1H), 3.76 (s, 3H), 3.50 - 3.37 (m, 1H), 3.17 (s, 3H), 2.37 (s, 3H),
1.61 - 1.44 (m, 2H), 1.02 - 0.74 (m, 1H), 0.68 - 0.45 (m, 2H), 0.30 - 0.06 (m, 2H).
Example 26
(S)-8-(2-amino-3-cyclobutylpropoxy)-4,6,9-trimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0254]

[0255] The title compound was prepared as described in Example 25 starting from (
S)
-tert-butyl (1-cyclobutyl-3-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate, prepared as described in Example
22, Part A to afford (
S)-8-(2-amino-3-cyclobutylpropoxy)-4,6,9-trimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (18 mg, 0.046 mmol, 26 % yield for the final step) as a hazy film. LC/MS, (ESI)
m/
z 366.3 [(M+H)
+, calcd for C
22H
28N
3O
2 366.2]; HPLC retention time (method C):
tR = 14.65 min; HPLC retention time (method D):
tR = 15.04 min;
1H NMR (400MHz, CHLOROFORM-d) δ 8.62 (d,
J=5.8 Hz, 1H), 7.95 (s, 1H), 7.82 (d,
J=5.8 Hz, 1H), 6.69 (s, 1H), 4.05 (dd,
J=8.8, 4.0 Hz, 1H), 3.88 (dd,
J=8.5, 7.3 Hz, 1H), 3.74 (s, 3H), 3.34 - 3.20 (m, 1H), 3.16 (s, 3H), 2.63 - 2.46 (m,
1H), 2.36 (s, 3H), 2.23 - 2.08 (m, 2H), 2.01 - 1.59 (m, 6H).
Example 27
(S)-8-((2-amino-4-methylpentyl)oxy)-9-(difluoromethyl)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0256]

Part A: 8-chloro-9-iodo-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0257] To a solution of 8-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (1 g, 3.87 mmol) prepared as described in Example 16, Part G, in acetic acid
(30 mL) was added H
2SO
4 (0.021 mL, 0.387 mmol) and periodic acid (0.881 g, 3.87 mmol). The solution was heated
at 80°C for 20 min then iodine (0.294 g, 1.160 mmol) was added. The mixture was stirred
for another 3 h at 80°C. The solution was cooled to room temperature then concentrated
under reduced pressure. EtOAc was added to the residue and the layer was washed with
saturated aqueous NaHCO
3 then H
2O. The combined organic layers were dried over Na
2SO
4, filtered and concentrated under reduced pressure to afford 8-chloro-9-iodo-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (1.2 g, 3.12 mmol, 81% crude yield) as an off-white solid. The material was
carried on without further purification. LC/MS (ESI)
m/
e 385.0 [(M+H)
+, calcd for C
14H
11ClIN
2O, 385.0]; LC/MS retention time (method B):
tR = 1.09 min.

Part B: 8-chloro-4,6-dimethyl-9-vinylbenzo[c][2,7]naphthyridin-5(6H)-one
[0258] A solution of 8-chloro-9-iodo-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (1.2 g, 2.71 mmol), 2,4,6-trivinylcyclotriboroxane pyridine complex (0.784 g,
3.26 mmol), tetrakis(triphenylphosphine)palladium (0.157 g, 0.136 mmol) and Na
2CO
3 (0.575 g, 5.43 mmol) in toluene (30 mL) and water (0.5 mL) was purged with nitrogen
and heated at 90°C for 16 h. After cooling to room temperature, the mixture was concentrated
under reduced pressure. The residue was taken up in ethyl acetate and filtered through
diatomaceous earth (Celite
®). The EtOAc layer was washed with brine and water. The combined organic layers were
dried over Na
2SO
4, filtered and concentrated under reduced pressure. The crude material was purified
by silica gel flash chromatography using EtOAc-hexane as the eluent to afford 8-chloro-4,6-dimethyl-9-vinylbenzo[
c][2,7]naphthyridin-5(6
H)-one (0.6 g, 1.43 mmol, 68% yield)) as brown gummy solid. LC/MS (ESI) m/e 285.0 [(M+H)
+, calcd for C
16H
14ClN
2O, 285.1]; LC/MS retention time (method B):
tR = 2.25 min.

Part C: 8-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carbaldehyde
[0259] To a solution of 8-chloro-4,6-dimethyl-9-vinylbenzo[c][2,7]naphthyridin-5(6
H)-once (600 mg, 2.107 mmol), osmium tetroxide (2.5% in 2-methyl-2-propanol) (0.794
mL, 0.063 mmol), and 2,6-dimethylpyridine (0.491 mL, 4.21 mmol) in 1,4-dioxane (30
mL) and water (30 mL) cooled to 0°C was added sodium periodate (1803 mg, 8.43 mmol).
The mixture was warmed to room temperature and stirred for 3 h. The mixture was diluted
with ethyl acetate and filtered through diatomaceous earth (Celite
®). The organic layer was concentrated under reduced pressure to afford a brown solid.
The solid was washed with hexane (3x20 mL) and dried under vacuum to afford 8-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carbaldehyde 0.6 g, 2.107 mmol, 84% yield) as a gummy brown
solid. LC/MS (ESI)
m/
e 287.0 [(M+H)
+, calcd for C
15H
12ClN
2O
2, 287.1]; LC/MS retention time (method B):
tR = 2.03 min.

Part D: 8-chloro-9-(difluoromethyl)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0260] To a solution of 8-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7] naphthyridine-9-carbaldehyde (600 mg, 1.779 mmol) in DCM (15 mL) was added
bis-(2-methoxyethyl)aminosulfur trifluoride (Deoxo-Fluor) (1.968 g, 8.89 mmol). The
mixture was then heated at 40°C for 3 h. After cooling to room temperature, the reaction
mixture was diluted with DCM and the DCM layer washed with saturated aqueous NaHCO
3 then H
2O, dried over Na
2SO
4, filtered and concentrated under reduced pressure. The residue was purified by silica
gel flash chromatography using EtOAc-hexane as the eluent to afford 8-chloro-9-(difluoromethyl)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (0.7 g, 1.519 mmol, 84% yield) as an off-white solid. LC/MS (ESI)
m/
e 309.0 [(M+H)
+, calcd for C
15H
12ClF
2N
2O, 309.1]; LC/MS retention time (method B):
tR = 2.38 min.
1H NMR (400 MHz,
METHANOL-d4) δ ppm 8.68 - 8.74 (m, 2H), 8.32 (d, 1H), 7.78 (s, 1H), 7.00 - 7.33 (m, 1H), 3.79
(s, 3H), 3.13 (s, 3H).

Part E: (S)-tert-butyl (1-((9-(difluoromethyl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0261] A solution of 8-chloro-9-(difluoromethyl)-4,6-dimethylbenzo[c][2,7]naphthyridin -5(6
H)-one (700 mg, 1.519 mmol), (
S)-
tert-butyl (1-hydroxy-4-methylpentan-2-yl)carbamate (660 mg, 3.04 mmol), 2-di-t-butylphosphino-2',4',6'-tri-i-propyl-1,1'-biphenyl
(387 mg, 0.912 mmol), PdOAc
2 (34.1 mg, 0.152 mmol) and Cs
2CO
3 (990 mg, 3.04 mmol) in toluene (20 mL) was heated at 80°C for 16 h. After cooling
to room temperature, the mixture was concentrated under reduced pressure.. The residue
was taken up in ethyl acetate and filtered through diatomaceous earth (Celite
®). The organic layer was washed with brine and water; dried over Na
2SO
4, filtered and concentrated under reduced pressure. The residue was purified by silica
gel flash chromatography using EtOAc-hexane as the eluent to afford (
S)-
tert-butyl (1-((9-(difluoromethyl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.6 g, 0.58 mmol, 54%
yield) as a brown gummy solid. LC/MS (ESI)
m/
e 490.2 [(M+H)
+, calcd for C
26H
14F
2N
3O
4, 490.2]; LC/MS retention time (method B):
tR = 2.72 min.

Part F: (S)-8-((2-amino-4-methylpentyl)oxy)-9-(difluoromethyl)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0262] To a solution of (
S)-
tert-butyl (1-((9-(difluoromethyl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
(500 mg, 0.480 mmol) in MeOH (10 mL) at 0°C was added 4N HCl in 1,4-dioxane (20 mL,
80 mmol). The solution was warmed to room temperature and stirred for 2 h. The mixture
was then was concentrated under reduced pressure. The residue was taken up in EtOAc
and the EtOAc layer was washed with saturated aqueous NaHCO
3 then H
2O, dried over Na
2SO
4, filtered and concentrated under reduced pressure. The residue was purified by prep.
HPLC to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-9-(difluoromethyl)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (60 mg, 0.149 mmol, 31% yield) as pale yellow solid. LC/MS (ESI)
m/
e 390.2 [(M+H)
+, calcd for C
21H
26F
2N
3O
2, 390.2]; LC/MS retention time (method A):
tR = 2.09 min; HPLC retention time (method A):
tR = 10.1 min; HPLC retention time (method B):
tR = 9.18 min;
1H NMR (400 MHz,
METHANOL-d4) δ ppm 8.73 (s, 1H), 8.66 (s, 2H), 7.07 - 7.41 (m, 2H), 4.66 - 4.53 (m, 1H), 4.52
- 4.49 (m, 1H), 3.78 - 3.89 (m, 4H), 3.22 (s, 3H), 1.74 - 1.88 (m, 2H), 1.63 - 1.71
(m, 1H), 1.04 (m, 6H).
Example 28
tert-butyl (2,4-dimethyl-1-((6-methyl-5-oxo-5,6 dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0263]

Part A. tert-butyl (2,4-dimethyl-1-((6-methyl-5-oxo-5,6-
[0264] dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate 8-Chloro-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (0.15 g, 0.613 mmol), prepared as described in Example 2, Part C, and
tert-butyl (1-hydroxy-2,4-dimethylpentan-2-yl)carbamate (0.284 g, 1.226 mmol) were subjected
to ether synthesis as described in Example 2, Part D, to afford
tert-butyl(2,4-dimethyl-1-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (0.3 g, 28% yield) as pale yellow
solid. LC/MS (ESI) m/e 440.2 [(M+H)
+, calcd for C
25H
14N
3O
4 440.2]; LC/MS retention time (method C):
tR = 2.67 min.

Part B. 8-((2-amino-2,4-dimethylpentyl)oxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0265] tert-Butyl (2,4-dimethyl-1-((6-methyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate was taken further for deprotection
of Boc as described in example 2, part E to afford 8-((2-amino-2,4-dimethylpentyl)oxy)-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one (30 mg, 12% yield) as off white solid. LC/MS (ESI)
m/
e 340.0 [(M+H)
+, calcd for C
20H
26N
3O
2, 340.2]; LC/MS retention time (method G):
tR = 1.88 min.
1H NMR (400 MHz,
METHANOL-d4) δ ppm 9.43 (s, 1H), 8.73 (d,
J=6.0 Hz, 1H), 8.35 (d,
J=8.5 Hz, 1H), 8.19 (d,
J=6.0 Hz, 1H), 7.12 - 7.01 (m, 2H), 4.05 - 3.92 (m, 2H), 3.77 (s, 3H), 1.95-1.80 (m,
1H), 1.58 (qd,
J=14.2, 5.5 Hz, 2H), 1.30 (s, 3H), 1.04 (d,
J=6.5 Hz, 3H), 1.01 (d,
J=6.5 Hz, 3H). Chiral HPLC (Method CHIRALPAK AD-H (250x4.6) mm, 5 micron, Mob. Phase
CO
2 (65%), Co-solvent 0.3% DEA in MeOH (35%), Back pressure 101), Chiral SFC retention
time
tR1 = 5.44 min; Chiral SFC retention time
tR2 = 7.77 min.
Example 29
8-((2-amino-2,4-dimethylpentyl)oxy)-7-fluoro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0266]

Part A. Methyl 4-chloro-2-methylnicotinate
[0267] To a solution of methyl 2,4-dichloronicotinate (10.0 g, 48.5 mmol) in a solvent mixture
of 1,4-dioxane (400 mL) and water (40 mL) was added trimethylboroxine (6.79 mL, 48.5
mmol) followed by PdCl
2(dppf)-CH
2Cl
2 adduct (1.982 g, 2.427 mmol) and cesium carbonate (31.6 g, 97 mmol). The reaction
mixture was degassed with argon for 5 minutes. The reaction mixture was heated to
reflux for 8 h. The reaction mixture was cooled to room temperature and filtered through
diatomaceous earth (Celite
®). The bed was washed with ethyl acetate and the combined filtrate was concentrated
under reduced pressure to afford the crude product which was purified by silica gel
column chromatography (gradient of ethyl acetate and petroleum ether) to afford methyl
4-chloro-2-methylnicotinate (5.20 g, 28 mmol, 58% yield) as a yellow liquid. LC/MS
(ESI)
m/
e 185.7 [(M+H)
+, calcd for C
8H
8ClNO
2 185.6]; LC/MS retention time (method G):
tR = 1.90 min.

Part B. Methyl 4-iodo-2-methylnicotinate
[0268] To a solution of methyl 4-chloro-2-methylnicotinate (6.00 g, 32.3 mmol) in acetonitrile
(80 mL) was added acetyl chloride (3.45 mL, 48.5 mmol) followed by sodium iodide (48.5
g, 323 mmol). The reaction mixture was heated at 80°C for 16hrs. The reaction mixture
was evaporated to dryness and the residue was adjusted to pH 6 by adding saturated
potassium carbonate solution. The product was extracted with dichloromethane (250
mL). The organic phase was washed with brine (2x100 mL), dried over Na
2SO
4, and concentrated under reduced pressure to afford methyl 4-iodo-2-methylnicotinate
(2.00 g, 7.22 mmol, 22% crude yield) as colorless semisolid which was carried on without
further purifications. LC/MS (ESI)
m/
e 278.0 [(M+H)
+, calcd for C
8H
9INO
2 278.0]; LC/MS retention time (method C):
tR = 2.13 min.

Part C. Methyl 4-(4-bromo-2,3-difluorophenyl)-2-methylnicotinate
[0269] In a microwave vessel, methyl 4-iodo-2-methylnicotinate (1.00 g, 3.61 mmol) was taken
in a mixture of 1,4-dioxane (18 mL) and water (2 mL) under inert atmosphere. (4-bromo-2,3-difluorophenyl)boronic
acid (1.03 g, 4.33 mmol) and Na
2CO
3 (765 mg, 7.22 mmol) were added to the reaction mixture and degassed for 5 minutes.
Pd(Ph
3P)
4 (83 mg, 0.072 mmol) was added to the reaction mixture and heated in microwave at
110°C for 90 min. The reaction mixture was diluted with water (150 mL) and extracted
with ethyl acetate (200 mL). The organic phase was washed with brine (2x100 mL), dried
over Na
2SO
4, and concentrated under reduced pressure. The residue was purified by silica gel
chromatography (gradient of ethyl acetate and petroleum ether) to afford methyl 4-(4-bromo-2,3-difluorophenyl)-2-methylnicotinate
(540 mg, 1.58 mmol, 44% yield) as a yellow liquid. LC/MS (ESI)
m/
e 344.0 [(M+2H)
+, calcd for C
14H
12BrF
2NO
2 344.1]; LC/MS retention time (method C):
tR = 2.48 min.

Part D. 4-(4-bromo-2,3-difluorophenyl)-2-methylnicotinic acid
[0270] To a solution of methyl 4-(4-bromo-2,3-difluorophenyl)-2-methylnicotinate (800 mg,
2.34 mmol) in MeOH (10 mL) was added NaOH (935 mg, 23.38 mmol) in Water (10 mL). The
reaction mixture was stirred at room temperature for 16hrs. The reaction mixture was
evaporated under reduced pressure and the residue obtained was adjusted to pH ~3 by
adding 1.5N HCl solution. The product was extracted with dichloromethane and the layers
were separated. The organic phase was dried over Na
2SO
4, and concentrated under reduced pressure to afford 4-(4-bromo-2,3-difluorophenyl)-2-methylnicotinic
acid (700 mg, 2.133 mmol, 91 % crude yield) as an off-white solid which was carried
on without further pruification. LC/MS (ESI)
m/
e 330.0 [(M+2H)
+, calcd for C
13H
10BrF
2NO
2 330.1]; LC/MS retention time (method C):
tR = 1.34 min.

Part E. 4-(4-bromo-2,3-difluorophenyl)-N,2-dimethylnicotinamide
[0271] To a solution of 4-(4-bromo-2,3-difluorophenyl)-2-methylnicotinic acid (700 mg, 2.13
mmol) in dichloromethane (20 mL) at 0 °C was added oxalyl chloride (0.56 mL, 6.40
mmol) drop wise followed by DMF (0.03 mL, 0.43 mmol). The reaction mixture was heated
to 45 °C for 4h. The reaction mixture was evaporated to dryness. The residue was taken
in dichloromethane (50 mL) at 0 °C and methylamine hydrochloride (1.56 g, 23.08 mmol)
was added to it followed by triethylamine (4.83 mL, 34.6 mmol). The reaction mixture
was stirred at room temperature for 2h. The reaction mixture was diluted with water
(50 mL) and extracted with dichloromethane (100 mL). The organic layer was separated,
dried over Na
2SO
4 and concentrated under reduced pressure to afford 4-(4-bromo-2,3-difluorophenyl)-
N,2-dimethylnicotinamide (600 mg, 1.76 mmol, 76% crude yield) as yellow semi-solid
which was carried on without further purification. LC/MS (ESI)
m/
e 343.0 [(M+2H)
+, calcd for C
14H
13BrF
2N
2O 343.0]; LC/MS retention time (method C):
tR = 1.61 min.

Part F. 8-bromo-7-fluoro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0272] To a solution of 4-(4-bromo-2,3-difluorophenyl)-N,2-dimethylnicotinamide (600 mg,
1.76 mmol) in tetrahydrofuran (20 mL) at 0 °C was added NaH (176 mg, 4.40 mmol) and
the reaction mixture was brought to room temperature gradually. The reaction mixture
was stirred at room temperature for 15h. The reaction mixture was diluted with water
(50 mL) and extracted with ethyl acetate (100 mL). The organic layer was separated,
dried over Na
2SO
4 and concentrated under reduced pressure to afford 8-bromo-7-fluoro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (400 mg, 1.24 mmol, 71% yield) as yellow solid. LC/MS (ESI)
m/
e 322.8 [(M+2H)
+, calcd for C
14H
12BrFN
2O 322.9]; LC/MS retention time (method G):
tR = 2.21 min.

Part G. tert-butyl (1-((7-fluoro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-2,4-dimethylpentan-2-yl)carbamate
[0273] To a stirred solution of 8-bromo-7-fluoro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (350 mg, 1.090 mmol) and
tert-butyl (1-hydroxy-2,4-dimethylpentan-2-yl)carbamate (504 mg, 2.180 mmol) in toluene
(10 mL) was added cesium carbonate (355 mg, 1.09 mmol) and 2-Di-t-butylphosphino-2',4',6'-tri-i-propyl-1,1'-biphenyl
(28 mg, 0.065 mmol). The reaction mixture was degassed with argon for 5 min and then
palladium acetate (7.34 mg, 0.033 mmol) was added to it. The reaction mixture was
heated to 100 °C for 18 h. Then, it was filtered through diatomaceous earth (Celite
®) and the filtrate was evaporated to afford
tert-butyl (1-((7-fluoro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-2,4-dimethylpentan-2-yl)carbamate which was taken to
next step without purification. LC/MS (ESI)
m/
e 472.2 [(M+H)
+, calcd for C
26H
35FN
3O
4 472.2]; LC/MS retention time (method C):
tR = 2.17 min.

Part H. 8-((2-amino-2,4-dimethylpentyl)oxy)-7-fluoro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0274] To a solution of
tert-butyl (1-((7-fluoro-4,6-dimethyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-2,4-dimethylpentan-2-yl)carbamate (200 mg, 0.424 mmol)
in MeOH (6 mL) at 0 °C was added 4M HCl in 1,4-dioxane (3 mL, 99.0 mmol). The reaction
mixture was stirred at 0 °C for 2h. After 2h, the reaction mixture was concentrated
under reduced pressure to afford crude product which was purified by preparative HPLC
to afford 8-((2-amino-2,4-dimethylpentyl)oxy)-7-fluoro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (10 mg, 0.024 mmol, 6% yield) as an off-white solid. LC/MS (ESI)
m/
e 372.0 [(M+H)
+, calcd for C
21H
27FN
3O
2 372.2]; LC/MS retention time (method G):
tR = 1.99 min. HPLC retention time (method A):
tR = 8.37 min; HPLC retention time (method B):
tR = 9.72 min.
1H NMR (400MHz,
METHANOL-d4) δ ppm 8.58 (d,
J= 6 Hz, 1 H), 8.22 (dd,
J= 9.2 Hz,
J= 2 Hz, 1 H), 8.14 (d,
J= 6 Hz, 1 H), 7.23 (m, 1 H), 4.31 (d,
J= 10 Hz, 1 H), 4.23 (d,
J = 10.4 Hz, 1 H), 3.88 (d,
J= 9.2 Hz, 3 H), 3.06 (s, 3 H), 1.90 (m, 2 H), 1.73 (m, 1 H), 1.52 (s, 3 H), 1.05 (m,
6H).
Example 30 & Example 31
8-(((5)-2-amino-4-methylpentyl)oxy)-9-(1-hydroxyethyl)-4,6 dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0275]

Part A. (S)-tert-butyl 1-(4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0276] Preparation as described in Example 16, Part H.

Part A. (S)-tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo 5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0277] (
S)-
tert-Butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate, prepared as described
in Example 16, Part H, was subjected to bromination following the condition mentioned
in Example 3, Part A to afford (
S)-
tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo 5,6dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (1.6 g, 2.62 mmol, 77%
yield) as pale yellow solid. LC/MS (ESI)
m/
e 518.2 [(M)
+, calcd for CH
33BrN
3O
4 518.1]; LC/MS retention time (method C):
tR = 2.46 min.

Part B. (S)-tert-butyl (1-((9-(1-ethoxyvinyl)-4,6 dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2yl)carbamate
[0278] To a solution of (
S)-
tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (500 mg, 0.964 mmol) in
1,4-dioxane (5 mL), tributyl(1-ethoxyvinyl)stannane (697 mg, 1.929 mmol), tris(dibenzylideneacetone)dipalladium
(0) (88 mg, 0.096 mmol) and DPPF (53.5 mg, 0.096 mmol) were added. The reaction mixture
was allowed to stir at 100 °C for 12h. The reaction mixture was diluted with water
and extracted in ethyl acetate. The organic layer was dried over sodium sulfate and
concentrated which afforded (
S)-
tert-butyl (1-((9-(1-ethoxyvinyl)-4,6 dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
(0.3 g, 0.33 mmol, 34% crude yield) as brown solid which was carried on without further
purification. LC/MS (ESI)
m/
e 510.2 [(M+H)
+, calcd for C
29H
40N
3O
5, 510.3]; LC/MS retention time (Method = C):
tR = 2.60 min.

Part C. (S)-9-acetyl-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0279] (
S)-
tert-Butyl (1-((9-(1-ethoxyvinyl)-4,6-dimethyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (200 mg, 0.392 mmol) was
treated with hydrochloric acid in 1,4-dioxane (981 µL, 3.92 mmol) at 0 °C. The reaction
mixture was allowed to stir at RT for 2h and then evaporated to dryness. The crude
material was neutralized with aqueous 10% NaHCO
3 and extracted with ethyl acetate. The organic layer was dried over Na
2SO
4 and concentrated which afforded (
S)-9-acetyl-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (0.11 g, 0.164 mmol, 42% yield) as brown solid. The material was carried on
without further purification. LC/MS (ESI)
m/
e 382.2 [(M+H)
+, calcd for C
22H
28N
3O
3, 382.2]; LC/MS retention time (method E):
tR = 0.78 min.

Part D. 8-(((S)-2-amino-4-methylpentyl)oxy)-9-(1-hydroxyethyl)-4,6-dimethylbenzo[c][2,7]naphthyri
din-5(6H)-one
[0280] To a solution of (
S)-9-acetyl-8-((2-amino-4-methylpentyl)oxy)-4,6 dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (100 mg, 0.257 mmol) in Ethanol (2 mL) was added NaBH
4 (97 mg, 2.57 mmol) at 0 °C. The reaction mixture was allowed to stir at RT for 16h.
Then, it was quenched with NH
4Cl, diluted with water and extracted in ethyl acetate. The combined organic layers
were dried over Na
2SO
4 and concentrated. The crude reaction mixture was purified by prep. HPLC which afforded
8-((
(S)-2-amino-4-methylpentyl)oxy)-9-(1-hydroxyethyl)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (0.03 g, 27% yield) as pale yellow semi-solid. LC/MS (ESI)
m/
e 384.1 [(M+H)
+, calcd for C
22H
30N
3O
3, 384.2]; LC/MS retention time (method E):
tR = 0.73 min. 96533-072 - Chiral separation was done which afforded two diastereomers
as off-white solid. Diastereomer-1 was eluted at retention time (HPLC Column : (250X30X5µ)
M.Phase A: 0.2% DEA Hexane; M, phase B:Ethanol):
tR = 21.9 min. 96533-072-11 -
1H NMR (400 MHz, METHANOL-
d4): ppm 1.01 - 1.07 (m, 6H), 1.55 (d,
J=6.46 Hz, 4H), 1.58 - 1.68 (m, 1H), 1.83 - 1.92 (m, 1H), 3.09 (s, 3H), 3.35 (d,
J=1.69 Hz, 1H), 3.80 (s, 3H), 4.13 - 4.19 (m, 1H), 4.28 - 4.34 (m, 1H), 5.32 (d,
J=6.46 Hz, 1H), 7.04 (s, 1H), 8.16 (d,
J=5.84 Hz, 1H), 8.47 (s, 1H), 8.58 (d,
J=5.77 Hz, 1H).
Diastereomer-2 was eluted at retention time (HPLC Column : (250X30X5µ) M.Phase A:
0.2% DEA Hexane; M, phase B:Ethanol)
tR = 24.9 min. 96533-072-12 -
1H NMR (400 MHz, METHANOL-
d4): ppm 1.03 (t,
J=6.84 Hz, 6H), 1.43 - 1.58 (m, 5H), 1.88 (dt,
J=13.73, 6.97 Hz, 1H), 3.09 (s, 3H), 3.35 (d,
J=1.69 Hz, 1H), 3.80 (s, 3H), 4.03 - 4.13 (m, 1H), 4.21 - 4.29 (m, 1H), 5.31 (d,
J=6.40 Hz, 1H), 7.03 (s, 1H), 8.15 (d,
J=5.84 Hz, 1H), 8.47 (s, 1H), 8.57 (d,
J=5.77 Hz, 1H).
Example 32
8-((2-amino-2,4-dimethylpentyl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyri din-5(6H)-one
[0281]

Part A. tert-butyl(1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-2,4-dimethylpentan-2-yl)carbamate
[0282] 8-Chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (0.15 g, 0.580 mmol), prepared as described in Example 16, Part G, and
tert-butyl (1-hydroxy-2,4-dimethylpentan-2-yl)carbamate (0.161 g, 0.696 mmol) were subjected
to the Buchwald coupling as described in Example 16, Part H, to afford
tert-butyl(1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-2,4-dimethylpentan-2-yl)carbamate (0.22 g, 0.199 mmol,
34% crude yield). Crude product was used for next step without further purification.
LC/MS (ESI)
m/
e 454.1 [(M+H)
+, calcd for C
26H
36N
3O
4, 454.3]; LC/MS retention time (method D):
tR = 0.93 min.

Part B. 8-((2-amino-2,4-dimethylpentyl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyri din-5(6H)-one
[0283] tert-Butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-2,4-dimethylpentan-2-yl)carbamate
(0.22 g, 0.199 mmol) was subjected to de-protection of the Boc group using the procedure
described in Example 2, Part E to give 8-((2-amino-2,4-dimethylpentyl)oxy)-4,6 dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (8 mg, 0.022 mmol, 11% yield) as white solid. LC/MS (ESI)
m/
e 354.2 [(M+H)
+, calcd for C
21H
28N
3O
2, 354.2]; LC/MS retention time (method C):
tR = 1.57 min. HPLC retention time (method A):
tR = 8.67 min; HPLC retention time (method B):
tR = 9.46 min.
1H NMR (400 MHz,
METHANOL-d4) ppm δ 8.54 (s, 1H), 8.34-8.36 (bs, 1H), 8.10 (bs, 1H), 7.06 (s, 1H), 4.11-4.17
(m, 2H), 3.73 (s, 3H), 3.06 (s, 3H), 1.70 - 1.98 (m, 2H), 1.68 (bs, 1H), 1.45 (s,
3H),1.02 - 1.08 (m, 6H).
Example 33
8-(((2S,3S)-3-amino-5-methylhexan-2-yl)oxy)-4,6 dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0284]

Part A. (S)-tert-butyl (4-methyl-1-oxopentan-2-yl)carbamate
[0285] To a solution of (
S)-
tert-butyl (1-hydroxy-4-methylpentan-2-yl)carbamate (2 g, 9.20 mmol) in DCM (30 mL) was
added Dess-Martin Periodinane (5.86 g, 13.81 mmol) at 0 °C. The reaction mixture was
allowed to stir at RT for 16h. The reaction mixture was quenched with NaHCO
3, diluted with water and extracted in ethyl acetate. Organic layer was dried over
Na
2SO
4 and concentrated which afforded (S)-
tert-butyl (4-methyl-1-oxopentan-2-yl)carbamate as colorless oil (1.4 g, 6.50 mmol, 71%
crude yield). The material was carried on without further purification.
1H NMR (300 MHz, DMSO-
d6): δ 0.8-0.96 (m, 6H), 1.31-1.49 (m, 11H), 1.57-1.66 (m, 1H), 3.81-3.89 (m, 1H). 7.27
(d, 1H), 9.43 (s, 1H).

Part B. tert-butyl ((3S)-2-hydroxy-5-methylhexan-3-yl)carbamate
[0286] A solution of (
S)-
tert-butyl (4-methyl-1-oxopentan-2-yl)carbamate (1.3 g, 6.04 mmol) in diethyl ether (50
mL) was cooled to -78 °C and treated with methyl magnesium bromide (1.4 M in diethy
ether) (8.63 mL, 12.08 mmol). The slurry was stirred at 0 °C for 1h and then stirred
for an additional hour at RT. The reaction mixture was quenched with NH
4Cl. The reaction mixture was extracted with diethyl ether (3 x 100 mL). The combined
organic layers were washed with brine, dried over MgSO
4, and concentrated to afford the product,
tert-butyl ((3
S)-2-hydroxy-5-methylhexan-3-yl)carbamate (1 g, 4.32 mmol, 72 % crude yield) as colorless
oil. The material was carried on without further purification.
1H NMR (300 MHz, DMSO-
d6): δ 0.78-0.93 (m, 6H), 0.98 (d, 3H), 1.11-1.41 (m, 2H), 1.42 (s, 9H), 1.45-1.64 (m,
1H), 3.30-3.63 (m, 2H), 4.37 (d, 1H), 6.19 (d, 1H).

Part C. tert-butyl ((3S)-2-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-5-methylhexan-3-yl)carbamate
[0287] A mixture of 8-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(d
H)-one (0.05 g, 0.193 mol),
tert-butyl ((3
S)-2-hydroxy-5-methylhexan-3-yl)carbamate (0.067 g, 0.290 mmol), Cs
2CO
3 (0.315 g, 0.966 mol), 2-di-
t-butylphosphino-2',4',6'-tri-
i-propyl-1,1'-biphenyl (8.21 mg, 0.019 mol) and Pd(OAc)
2 (2.60 mg, 0.012 mol) were taken in Toluene (2 mL) and heated overnightat 90 °C. After
cooling the reaction mixture was concentrated, then diluted with ethyl acetate and
water. Ethyl acetate layer was collected, dried over Na
2SO
4, filtered and concentrated which afforded
tert-butyl((3
S)-2-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-5-methylhexan-3-yl)carbamate, (70 mg, 0.154 mmol, 80%
crude yield) as brown solid. The crude product was used for next step without further
purification. LC/MS (ESI)
m/
e 454.2 [(M+H)
+, calcd for C
26H
16N
3O
4, 454.3]; LC/MS retention time (method D):
tR = 0.91 min.

Part D. 8-(((3S)-3-amino-5-methylhexan-2-yl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0288] tert-Butyl ((3
S)-2-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-5-methylhexan-3-yl)carbamate (0.16 g, 0.353 mmol) was
subjected to deprotection of the Boc group (procedure described in Example 2, Part
E) which afforded the diastereomeric mixture 8-(((3
S)-3-amino-5-methylhexan-2-yl)oxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (17 mg, 0.017 mmol, 5% yield) as a white solid. LC/MS (ESI)
m/
e 354.2 [(M+H)
+, calcd for C
21H
28N
3O
2, 354.2]; LC/MS retention time (method C):
tR = 1.56 min. HPLC retention time (method A):
tR = 9.40 min; HPLC retention time (method B):
tR = 9.36 min.
1H NMR (400MHz,
METHANOL-d4) 8.57 (d,
J=5.5 Hz, 1H), 8.41 (d,
J=9.0 Hz, 1H), 8.15 (d,
J=6.0 Hz, 1H), 7.15 - 7.06 (m, 2H), 4.68 (quin,
J=5.9 Hz, 1H), 3.76 (s, 4H), 3.09 (s, 3H), 1.88 - 1.50 (m, 3H), 1.44 (s, 3H), 1.03
(d,
J=6.5 Hz, 3H), 0.98 (d,
J=6.5 Hz, 3H).
Example 34
8-((2-amino-2,4-dimethylpentyl)oxy)-9-methoxy-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0289]

Part A. 9-bromo-8-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0290] To a solution of 8-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (0.2 g, 0.773 mmol) in acetonitrile (4 mL) at -30 °C was added trifluoroacetic
acid (0.089 mL, 1.160 mmol) and 1-bromopyrrolidine-2,5-dione (0.151 g, 0.850 mmol).
The mixture was heated to 80 °C overnight. The reaction mixture was concentrated,
diluted with ethyl acetate and excess aqueous 10% NaHCO
3. The ethyl acetate layer was concentrated. The residue was purified by prep. HPLC
to afforded 9-bromo-8-chloro-4,6 dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (120 mg, 0.351 mmol, 45% yield) as white solid. LC/MS (ESI)
m/
e 337.0 [(M+H)
+, calcd for C
14H
11BrClN
2O, 337.0]; LC/MS retention time (Method C):
tR = 2.55 min;
1H NMR (400 MHz, METHANOL-
d4) ppm 3.11 (s, 3H), 3.75 (s, 3H), 7.81 (s, 1H), 8.20-8.26 (m, 1H), 8.68 (d,
J=5.6 Hz, 1H), 8.79 (s, 1H).

Part B. 8-chloro-9-methoxy-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0291] A mixture of 9-bromo-8-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.05 g, 0.148 mmol), copper(I)iodide (0.031 g, 0.163 mmol), L-proline (0.020
g, 0.178 mmol), sodium methoxide (0.040 g, 0.741 mmol) and K
2CO
3 (0.041 g,0.296 mmol) were stirred in DMSO (1.5 mL). The mixture was heated to 80
°C for 16h. After cooling, the crude reaction mixture was diluted with methanol, filtered
through diatomaceous earth (Celite
®) and concentrated under reduced pressure to afford 8-chloro-9-methoxy-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one, as brown solid (40 mg). LC/MS (ESI)
m/
e 289.0 [(M)
+, calcd for C
15H
14ClN
2O
2, 289.1]; LC/MS retention time (method D):
tR = 0.89 min.

Part C. tert-butyl(1-((9-methoxy-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-2,4-dimethylpentan-2-yl)carbamate
[0292] 8-Chloro-9-methoxy-4,6-dimethylbenzo[c][2,7]naphthyridin-5(
6H)-one (0.04 g, 0.139 mmol) was subjected to Buchwald coupling (Example 16, Part H)
with
tert-butyl (1-hydroxy-2,4-dimethylpentan-2-yl)carbamate (0.048 g, 0.208 mmol) which afforded
tert-butyl(1-((9-methoxy-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8- yl)oxy)-2,4-dimethylpentan-2-yl)carbamate as white solid (15
mg, 0.029 mmol, 21% yield). LC/MS (ESI)
m/
e 484.2 [(M+H)
+, calcd for C
27H
38N
3O
5, 484.3]; LC/MS retention time (Method C):
tR = 2.42 min.

Part D. 8-((2-amino-2,4-dimethylpentyl)oxy)-9-methoxy-4,6 dimethylbenzo [c][2,7]naphthyridin-5 (6H)-one
[0293] tert-Butyl (1-((9-methoxy-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-2,4-dimethylpentan-2-yl)carbamate (0.015 g, 0.031 mmol)
was subjected to deprotection of the Boc group as per Example 2, Part E to afford
8-((2-amino-2,4-dimethylpentyl)oxy)-9-methoxy-4,6 dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (8 mg, 0.02 mmol, 63% yield) as a yellow solid. LC/MS (ESI)
m/
e 384.2 [(M+H)
+, calcd for C
22H
30N
3O
3, 384.5]; LC/MS retention time (Method C),
tR = 6.57 min.
1H NMR (400MHz, METHANOL-d
4) 8.63 (d,
J=6.0 Hz, 1H), 8.51 (br. s., 1H), 8.02 (s, 1H), 7.23 (s, 1H), 4.39 (d,
J=10.5 Hz, 1H), 4.32 - 4.24 (m, 1H), 4.10 (s, 3H), 3.83 (s, 3H), 3.19 (s, 3H), 1.99
- 1.86 (m, 2H), 1.73 (d,
J=9.0 Hz, 1H), 1.55 (s, 3H), 1.09 (d,
J=6.5 Hz, 3H), 1.05 (d,
J=6.5 Hz, 3H).
Example 35
(S)-8-((2-amino-4-methylpentyl)oxy)-9-(2-hydroxypropan-2-yl)-4,6-dimethylbenzo[c][2,7]naphthyridin-5 (6H)-one
[0294]

Part A. (S)-2-(1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione
[0295] 8-Chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H]-one (1.4 g, 5.41 mmol) and
(S)-2-(1-hydroxy-4-methylpentan-2-yl)isoindoline-1,3-dione (4.01 g, 16.23 mmol) were
subjected to Buchwald coupling as described in Example 16, Part H) to give
(S)-2-(1-((4,6-dimethyl-5-oxo 5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione as yellow solid
(1.4 g, 2.62 mmol, 49% yield). LC/MS (ESI)
m/
e 470.2 [(M+H)
+, calcd for C
28H
28N
3O
4 470.2]; LC/MS retention time (method C):
tR = 2.05 min.

Part B. (S)-2-(1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione
[0296] To a solution of
(S)-2-(1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (1g, 1.917
mmol) in acetonitrile (20 mL) was added NBS (0.341 g, 1.917 mmol) and the solution
heated to 80 °C overnight to afford
(S)-2-(1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (1.2 g, 1.69
mmol, 88% crude yield) as brown solid. The material was carried forward without further
purification. LC/MS (ESI)
m/
e 548.0 [(M+H)
+, calcd for C
28H
27BrN
3O
4 548.1; LC/MS retention time (method D):
tR = 0.76 min.

Part C. (S)-2-(1-((9-(1-ethoxyvinyl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione
[0297] A solution of
(S)-2-(1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (100 mg, 0.182
mmol), tributyl(1-ethoxyvinyl)stannane (132 mg, 0.365 mmol), DPPF (20.22 mg, 0.036
mmol) and Pd
2(dba)
3 (16.70 mg, 0.018 mmol) in 1,4-dioxane (5 mL) was purged with nitrogen for 5 min then
heated at 100 °C overnight. After cooling to ambient temperature, the volatiles were
concentrated under reduced pressure. The residue was thaken up in ethyl acetate and
filtered through diatomaceous earth (Celite
®). The organic filtrate was washed with H
2O, then brine, dried over Na
2SO
4 and concentrated under reduced pressure to afford
(S)-2-(1-((9-(1-ethoxyvinyl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (0.15 g, 0.131
mmol, 72% crude yield) as a black gummy solid. The material was carried forward without
further purification. LC/MS (ESI)
m/
e 540.3 [(M+H)
+, calcd for C
32H
34N
3O
5 540.2; LC/MS retention time (method G):
tR = 1.21 min.

Part D. (S)-2-(1-((9-acetyl-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione
[0298] (S)-2-(1-((9-(1-ethoxyvinyl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (150 mg, 0.278
mmol) was subjected to acid hydrolysis to afford
(S)-2-(1-((9-acetyl-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (0.1 g, 0.14
mmol, 51% yield) as brown solid. The crude material was carried forward without further
purification. LC/MS (ESI)
m/
e 512.1 [(M+H)
+, calcd for C
30H
30N
3O
5 512.2; LC/MS retention time (method D):
tR = 0.89 min.

Part E. (S)-2-(1-((9-(2-hydroxypropan-2-yl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione
[0299] To a solution of
(S)-2-(1-((9-acetyl-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (220 mg, 0.430
mmol) in THF (6 mL) was added methyl magnesium bromide (1.4 M in diethyl ether) (0.922
mL, 1.290 mmol) at -10°C and stirred for overnight at RT. The reaction mixture was
carefully quenched with water and diluted with EtOAc. The organic layer was separated,
dried over sodium sulphate and concentrated under reduced pressure. The residue was
purified via silica gel chromatography to afford
(S)-2-(1-((9-(2-hydroxypropan-2-yl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (0.2 g, 0.152
mmol, 35% yield) as a brown gummy solid. LC/MS (ESI)
m/
e 528.2 [(M+H)
+, calcd for C
31H
34N
3O
5 528.2; LC/MS retention time (method D):
tR = 0.89 min.

Part F. (S)-8-((2-amino-4-methylpentyl)oxy)-9-(2-hydroxypropan-2-yl)-4,6-dimethylbenzo [c][2,7]naphthyridin-5 (6H)-one
[0300] To a solution of
(S)-2-(1-((9-(2-hydroxypropan-2-yl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (200 mg, 0.152
mmol) in ethanol (5 mL), was added hydrazine (4.76 µl, 0. 152 mmol) at RT then the
mixture was heated to 60 °C for 4h. The reaction mixture was filtered, concentrated
and purified by prep. HPLC to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-9-(2-hydroxypropan-2-yl)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one as white solid (9 mg, 0.021 mmol, 14% yield). LC/MS (ESI)
m/
e 398.0 [(M+H)
+, calcd for C
23H
32N
3O
3 398.2]; LC/MS retention time (method G):
tR = 1.99 min. HPLC retention time (method A):
tR = 8.63 min; HPLC retention time (method B):
tR = 9.79 min.
1H NMR (400 MHz, METHANOL-
d4) ppm 0.94 - 1.10 (m, 6H), 1.25 - 1.37 (m, 1H), 1.49 - 1.78(m, 7H), 1.82 - 1.93 (m,
1H), 2.96 - 3.19 (m, 2H), 3.56 - 3.65 (m, 1H), 3.80 (s, 3H), 4.16 - 4.29 (m, 1H),
4.34 - 4.49 (m, 1H), 7.01 - 7.15 (m, 1H), 8.10 - 8.22 (m, 1H), 8.51 - 8.64 (m, 2H).
Example 36
(S)-8-((2-amino-4-methylpentyl)oxy)-9-ethyl-4,6-dimethylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0301]

Part A: (S)-tert-butyl (1-((4,6-dimethyl-5-oxo-9-vinyl-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0302] To the solution of
(S)-tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
(300 mg, 0.579 mmol), prepared as described in Example 3, Part A, in the solvent mixture
toluene (10 mL), water (0.5 mL) and ethanol (2 mL) was added sodium carbonate (184
mg, 1.736 mmol), tetrakis(triphenylphosphine)palladium (33.4 mg, 0.029 mmol) and 2,4,6-trivinyl-1,3,5,2,4,6-trioxatriborinane
with pyridine (1:1) (167 mg, 0.694 mmol). The reaction mixture was degassed for 30
min. Then the reaction mixture was allowed to stir at 90 °C for 16 h. After cooling
to room temperature the mixture was filtered through diatomaceous earth (Celite
®) eluting with EtOAc. The filtrate was concentrated under reduced pressure. The residue
was thaken up in EtOAc and water..The solution was extracted with ethyl acetate (2
x 15 mL). The combined organic layers were washed with water (10 mL), brine (10 mL),
dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue
was purified by silica gel column chromatography (60% Ethyl acetate in hexane) to
afford
(S)-tert-butyl (1-((4,6-dimethyl-5-oxo-9-vinyl-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
(300 mg, 0.110 mmol, 19% yield) as a pale yellow semi solid. LC/MS, (ESI)
m/
z 466.5 [(M+H)
+, calcd for C
27H
36N
3O
4 466.3]; LC/MS retention time (method E):
tR = 1.18 min.

Part B: (S)-tert-butyl (1-((9-ethyl-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0303] A solution of
(S)-tert-butyl (1-((4,6-dimethyl-5-oxo-9-vinyl-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (50 mg, 0.107 mmol) in
MeOH (3 mL) was degassed with nitrogen for 5 min, then palladium on carbon (1.143
mg, 10.74 µmol) was added. The reaction mixture was allowed to stir under a balloon
of hydrogen for 16 h. The reaction mixture was then filtered through diatomaceous
earth (Celite
®) and the filtrate was concentrated under reduced pressure. The residue was purified
by preparative TLC (2% MeOH in MDC) to afford
(S)-tert-butyl (1-((9-ethyl-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (31 mg, 0.058 mmol, 54%
yield) as pale yellow solid. LC/MS, (ESI)
m/
z 468.5 [(M+H)
+, calcd for C
27H
38N
3O
4 468.3]; LC/MS retention time (method D):
tR = 1.31 min.

Part C: (S)-8-((2-amino-4-methylpentyl)oxy)-9-ethyl-4,6-dimethylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0304] Prepared as described in Example 2, Part E to afford the title compound (4 mg, 10.62
µmoles, 33% yield) as a pale yellow gum. LC/MS, (ESI)
m/
z 368.4 [(M+H)
+, calcd for C
22H
30N
3O
2 368.2]; LC/MS retention time (method B):
tR = 2.18 min. HPLC retention time (method A):
tR = 8.87 min; HPLC retention time (method B):
tR = 9.53 min.
1H NMR (400 MHz, MeOH-
d4) δ ppm 8.51 (d,
J=5.60 Hz, 1H) 8.17 (s, 1H) 8.13 (d,
J=5.60 Hz,1H) 6.97 (s, 1H) 4.17-4.20(m, 1H) 4.04 - 4.04 (m, 1H) 3.76 (s, 3H) 3.31 -
3.38 (m, 1H) 3.06(s, 3H) 2.80 - 2.82 (m, 2H) 1.81- 1.89 (m, 1H) 1.53-1.58 (m, 1H)
1.45- 1.50 (m, 1H) 1.27 -1.31 (m, 3H), 0.98-1.02 (m, 6H).
Example 37 (Enantiomer 1) and Example 38 (Enantiomer 2)
(R)-8-((2-amino-2,4-dimethylpentyl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyri din-5(6H)-one and (S)-8-((2-amino-2,4-dimethylpentyl)oxy)-4,6-dimethylbenzo[c] [2,7]naphthyri din-5(6H)-one
[0305]

[0306] The resolution of 8-((2-amino-2,4-dimethylpentyl)oxy)-4,6 dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one, prepared in Exampl2 32, was carried out by chiral HPLC (Method: Co-solvent:
0.3% DEA in methanol, Column: Chiralpak AD H (250 x 21) mm 5u) resulting into two
enantiomers. The absoulte stereochemistry of each enantiomer was not determined. Enantiomer-1:
LC/MS (ESI)
m/
e 354.2 [(M+H)
+, calcd for C
21H
28N
3O
2,354.2]; LC/MS retention time (method C):
tR = 1.57 min. HPLC retention time (method A):
tR = 8.67 min; HPLC retention time (method B):
tR = 9.46 min.
1H NMR (400 MHz, METHANOL-
d4) ppm δ 8.54 (s, 1H), 8.34-8.36 (bs, 1H), 8.10 (bs, 1H), 7.06 (s, 1H), 4.11-4.17 (m,
2H), 3.73 (s, 3H), 3.06 (s, 3H), 1.70 - 1.98 (m, 2H), 1.68 (bs, 1H), 1.45 (s, 3H),1.02
- 1.08 (m, 6H); Chiral HPLC retention time,
tR = 9.36 min Enantiomer-2: LC/MS (ESI)
m/
e 354.2 [(M+H)
+, calcd for C
21H
28N
3O
2,354.2]; LC/MS retention time (method C):
tR = 1.57 min. HPLC (Method B) retention time (method A):
tR = 8.67 min; HPLC retention time (method B):
tR = 9.46 min.
1H NMR (400 MHz, METHANOL-
d4) ppm δ 8.54 (s, 1H), 8.34-8.36 (bs, 1H), 8.10 (bs, 1H), 7.06 (s, 1H), 4.11-4.17 (m,
2H), 3.73 (s, 3H), 3.06 (s, 3H), 1.70 - 1.98 (m, 2H), 1.68 (bs, 1H), 1.45 (s, 3H),1.02
- 1.08 (m, 6H); Chiral HPLC (Method B) retention time:
tR = 10.68 min.
Example 39
(S)-8-((2-(dimethylamino)-4-methylpentyl)oxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0307]

[0308] To a stirred solution of (
S)-8-((2-amino-4-methylpentyl)oxy)-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.06 g, 0.184 mmol) (synthesis described in Example 2, Part E) in formic acid
(0.035 mL, 0.922 mmol) was added formaldehyde (0.025 mL, 0.922 mmol) at ambient temperature.
Then reaction mixture was then heated to reflux for 16 h. The reaction mixture was
concentrated under reduced pressure. The residue was diluted with 50 mL of water and
extracted with 80 mL of dichloromethane. The organic layer wasseparated, dried over
sodium sulphate, and concentrated under reduced pressure. The residue was purified
by reverse phase HPLC (acetoniltrile/water/10 mM NH
4OAc) to afford
(S)-8-((2-(dimethylamino)-4-methylpentyl)oxy)-6 methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (8 mg, 0.021 mmol, 11% yield) as a white solid. LC/MS (ESI)
m/
e 354.0 [(M+H)
+, calcd for C
21H
28N
3O
2, 354.5]; LC/MS retention time (method C):
tR = 1.85 min. HPLC retention time (method A):
tR = 8.02 min; HPLC retention time (method B):
tR = 9.19 min
1 H NMR (400 MHz, METHANOL-
d4) δ ppm 1.01 (d, J = 6.80 Hz, 6H), 1.50-1.61 (m, 2H), 1.73-1.80 (m, 1H), 2.52 (s,
1H), 3.15-3.16 (m, 1H), 3.73 (s, 3H), 4.23-4.31 (m, 2H), 7.04 (d, J = 8.00 Hz, 2H),
8.15 (s, 1H), 8.30 (d, J = 8.00 Hz, 1H), 8.71 (s, 1H), 8.39 (s, 1H).
Example 40
(S)-8-((2-(dimethylamino)-4-methylpentyl)oxy)-4,6-dimethylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0309]

[0310] To a slurry of
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6 dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.1 g, 0.295 mmol) (synthesis described in Example 16, part I) in formic acid
(0.011 mL, 0.295 mmol) was added formaldehyde (8.12 µL, 0.295 mmol) at RT. The reaction
mixture was heated to 100 °C for 16 h in a sealed tube. After cooling to room temperature,
the mixture concentrated under reduced pressure. The residue was then partitioned
between water (50 mL) and dichloromethane (80 mL). The organic layer was separated,
dried over sodium sulfate and concentrated under reduced pressure. The resiude was
purified by reverse phase HPLC (10mM ammonium acetate/AcCN) to afford
(S)-8-((2-(dimethylamino)-4-methylpentyl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(
6H)-one (30 mg, 0.078 mmol, 26% yield) as a white solid. LC/MS (ESI)
m/
e 368.0 [(M+H)
+, calcd for C
22H
30N
3O
3, 368.2]; LC/MS retention time (Method C):
tR = 1.86 min. HPLC retention time (method A):
tR = 7.98 min; HPLC retention time (method B):
tR = 9.44 min.
1H NMR (400 MHz, METHANOL-
d4) ppm δ 1.01 (d,
J= 6.80 Hz, 6H), 1.61-1.95 (m, 3H), 2.66-2.69 (m, 6H), 3.06 (s, 3H), 3.37-3.43 (m, 1H),
3.74 (s, 3H), 4.37 (d,
J= 4.80 Hz, 2H), 7.04-7.08 (m, 2H), 8.10 (d,
J= 5.60 Hz, 1H), 8.36 (d,
J= 8.80 Hz, 1H), 8.53 (d,
J= 5.60 Hz, 1H).
Example 41
8-((2-amino-2,4-dimethylpentyl)oxy)-9-chloro-4,6 - dimethylbenzo [c][2,7]naphthyridin-5 (6H)-one
[0311]

[0312] To the stirred solution of 8-((2-amino-2,4-dimethylpentyl)oxy)-4,6 dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (Prepared in Example 32, Part B) (0.08 g, 0.226 mmol) in acetonitrile (5 mL)
was added NCS (0.030 g, 0.226 mmol)) at RT and the reaction mixture was stirred for
2h. The mixture was then evaporated to dryness. The residue was purified by reverse
phase HPLC (0.1%TFA in water/AcCN) to afford 8-((2-amino-2,4-dimethylpentyl)oxy)-9-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (12 mg, 0.030 mmol, 13% yield). LC/MS (ESI)
m/
e 388.0 [(M+H)
+, calcd for C
21H
27ClN
3O
2,388.2] as an off-white solid. LC/MS retention time (method C):
tR = 2.13 min. HPLC retention time (method A):
tR = 8.97 min; HPLC retention time (method B):
tR = 10.16 min.
1H NMR (400MHz, METHANOL-
d4) δ ppm 0.99-1.02 (m, 6H), 1.30 (s, 3H), 1.54-1.66 (m, 2H), 1.84-1.90 (m, 1H), 3.05
(s, 1H), 3.73 (s, 1H), 4.04 (q,
J= 23.20 Hz, 2H), 7.03 (s, 1H), 8.06 (d,
J= 6.00 Hz, 1H), 8.39 (s, 1H), 8.54 (d,
J= 6.00 Hz, 1H).
Example 42
(S)-8-(2-amino-4-methylpentyloxy)-4-methoxy-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0313]

Part A. 8-chloro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0314] Preparation as described in Example 2, Part C.

Part A. 8-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine 3-oxide
[0315] To the stirred solution of 8-chloro-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (1.0 g, 4.09 mmol), prepared as described in Example 2, Part C, in DCM (20 mL)
cooled to 0°C was added
m-CPBA (1.763 g, 10.22 mmol). The reaction mixture was then warmed to ambient temperature
and stirred for 4 h. Reaction mixture was then diluted with dichloromethane (100 mL)
and washed with saturated sodium bicarbonate solution (200 mL), brine solution (50
mL). The orgaincs were then dried over sodium sulphate, filtered and concentrate to
afford 8-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine 3-oxide (1.0
g, 3.84 mmol, 94 % crude yield) as a yellow solid. The material was carried on without
further purification. LC/MS (ESI)
m/
e 261.0, [(M+H)
+, calcd for C
13H
10ClN
2O
2, 261.0]; LC/MS retention time (method C):
tR = 1.65 min.

Part B. 4,8-dichloro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0316] A stirred solution of 8-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine 3-oxide (0.5 g, 1.918 mmol) in POCl
3 (3.58 mL, 38.4 mmol) was heated to reflux for 6 h. The reaction mixture was concentrated
under reduced pressure. The residue was then partitioned between dichloromethane (100
mL) and saturated sodium bicarbonate solution (200 mL). The organic layer was separated
and washed again with brine solution (50 mL), dried over sodium sulphate, and concentrated
to afford 4,8-dichloro-6 methylbenzo[c][2,7]naphthyridin-5(
6H)-one (0.3 g, 1.075 mmol, 56% crude yield). The material was carried on without further
purification. LC/MS (ESI)
m/
e 280.8, [(M+2H)
+, calcd for C
13H
9Cl
2N
2O, 280.8]; LC/MS retention time (method C):
tR = 2.06 min.

Part C. 8-chloro-4-methoxy-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0317] To a solution of 4,8-dichloro-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (1.0 g, 3.58 mmol) in MeOH (1 mL) was added sodium methoxide (0.806 mL, 3.58
mmol). The resultant mixture was heated in a microwave at 80°C for 25 min. The reaction
mixture was then diluted with water (20 mL) and extracted with ethyl acetate (30 mL).
The organic layer was separated, dried over sodium sulphate and evaporated to dryness
to afford 8-chloro-4-methoxy-6-methylbenzo[c][2,7]naphthyridin-5(
6H)-one (0.4 g, 1.391 mmol, 39% crude yield) as a brown solid. The material was carried
on without further purification. LC/MS (ESI)
m/
e 274.8 [(M+H)
+, calcd for C
14H
12ClN
2O
2, 275.0]; LC/MS retention time (method C):
tR = 2.06 min.

Part D. (S)-tert-butyl (1-((4-methoxy-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0318] Prepared as described in Example 16, Part H to afford the title product (0.1 g, 0.135
mmol, 62% yield) as a semi solid. LC/MS (ESI) m/e 456.0, [(M+H)
+, calcd for C
25H
34N
3O
5, 456.2]; LC/MS retention time (method C): t
R = 2.26 min.

Part E. (S)-8-((2-amino-4-methylpentyl)oxy)-4-methoxy-6 methylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0319] Prepared as described in Example 2, Part E to afford the title product (10 mg, 0.027
mmol, 20% yield) as a gum. LC/MS (ESI)
m/
e 356.0, [(M+H)
+, calcd for C
20H
26N
3O
3, 356.4]; LC/MS retention time (method C):
tR = 1.83 min. HPLC retention time (method A):
tR = 8.48 min; HPLC retention time (method B):
tR = 7.61 min.
1H NMR (400 MHz, METHANOL-
d4) δ ppm 8.24 (d,
J=6.0 Hz, 1H), 8.13 (d,
J=9.0 Hz, 1H), 7.62 (d,
J=6.0 Hz, 1H), 6.99 - 6.91 (m, 1H), 6.90 (d,
J=2.5 Hz, 1H), 4.11 (dd,
J=9.5
, 4.0 Hz, 1H), 4.06 (s, 3H), 3.92 (dd,
J=9.3, 7.3 Hz, 1H), 3.65 (s, 3H), 1.93 - 1.81 (m, 1H), 1.45 (td,
J=7.7, 6.3 Hz, 2H), 1.03 (d,
J=6.5 Hz, 3H), 1.01 (d,
J=6.5 Hz, 3H).
Example 43
(S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0320]

Part A. (S)-tert-butyl (1-((9-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0321] (S)-tert-butyl (4-methyl-1-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (0.4 g, 0.714 mmol), prepared as
described in Example 19, Part B, was subjected to chlorination using NCS as described
in Example 41, to afford
(S)-tert-butyl (1-((9-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.3 g, 0.437 mmol, 61%
yield) as a yellow solid. LC/MS (ESI)
m/
e 460.2 [(M+H)
+, calcd for C
24H
31ClN
3O
4,460.2]; LC/MS retention time (Method C)
tR = 2.17 min.

Part B. (S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-6 methylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0322] (S)-
tert-t-Butyl (1-((9-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
was subjected to deprotection of Boc, as described in Example 2, Part E, to afford
(
S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-6 methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.1 g, 0.27 mmol, 72% yield) as an off-white solid. LC/MS (ESI)
m/
e 360.2 [(M+H)
+, calcd for C
19H
23ClN
3O
2,360.1]; HPLC retention time (method A):
tR = 8.94 min; HPLC retention time (method B):
tR = 5.4 min.
1H NMR (400 MHz, METHANOL-
d4) ppm 9.43 (d,
J=0.50 Hz, 1H), 8.76 (d,
J=5.52 Hz, 1H), 8.42 (s, 1H), 8.16 - 8.20 (m, 1H), 7.10 (s, 1H), 4.23 - 4.27 (m, 1H),
4.02 - 4.08 (m, 1H), 3.78 (s, 3H), 3.34 - 3.40 (m, 1H), 1.84 - 1.94 (m, 1H), 1.42
- 1.58 (m, 2H), 1.03 (dd,
J=8.66, 6.65 Hz, 6H).
Example 44
(S)-8-(2-amino-4-methylpentyloxy)-6-(2-hydroxyethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0323]

Part A. 8-chloro-6-(2 -hydroxyethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0324] To a stirred solution of 8-chlorobenzo[
c][2,7]naphthyridin-5(
6H)-one (80 mg, 0.347 mmol) in anhydrous DMF (5 mL) under a nitrogen atmosphere was
added ethyl carbonate (122 mg, 1.387 mmol), K
2CO
3 (96 mg, 0.694 mmol), and 18-crown-6 (18.31 mg, 0.069 mmol). The reaction mixture
was heated to 80 °C for 12 h. The reaction mixture was diluted with water (10 mL)
nad extracted with ethyl acetate (2x20 mL). The combined ethyl acetate layers were
dried over sodium sulphate and concentrated under reduced pressure to afford 8-chloro-6-(2
- hydroxyethyl)benzo[
c][2,7]naphthyridin-5(
6H)-one (80 mg, 0.291 mmol, 84 % crude yield) The material was carried on without further
purification. LC/MS (ESI)
m/
e 275.0 [(M+H)
+, calcd for C
14H
12ClN
2O
2,275.1];
1H NMR (400 MHz,
MeOD) δ 9.55 (s, 1H), 8.87 (d,
J=5.6 Hz, 1H), 8.50 (d,
J=8.8 Hz, 1H), 8.34 (d,
J=5.6 Hz, 1H), 7.88 (d,
J=1.6 Hz, 1H), 7.44 (dd,
J=8.4, 2.0 Hz, 1H), 4.57 (t,
J=6.0 Hz, 2H), 3.96 (t,
J=6.0 Hz, 2H).

Part B. (S)-tert-butyl (1-((6-(2-hydroxyethyl)-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0325] Prepared as described in Example 16, Part H to afford
(S)-tert-butyl (1-((6-(2-hydroxyethyl)-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
(60 mg, 0.132 mmol, 45% yield) as a white oil, LC/MS (ESI)
m/
e 456.2, [(M+H)
+, calcd for C
25H
14N
3O
5, 456.2]; LC/MS retention time (method C):
tR = 1.81 min.

Part C. (S)-8-((2-amino-4-methylpentyl)oxy)-6-(2-hydroxyethyl)benzo[c] [2,7]naphthyridin-5(6H)-one
[0326] Prepared as described in Example 2, Part E to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-6-(2-hydroxyethyl)benzo[
c][2,7]naphthyridin-5(
6H)-one (6 mg, 0.015 mmol, 12% yield) as a yellow solid. LC/MS (ESI)
m/
e 356.2, [(M+H)
+, calcd for C20H26N3O3, 356.2]; LC/MS retention time (method C):
tR = 1.59 min. HPLC retention time (method A):
tR = 7.66 min; HPLC retention time (method B):
tR = 7.99 min.
1H NMR (400 MHz,
MeOD) δ 9.50 (s, 1H), 8.79 (d,
J=6.0 Hz, 1H), 8.47 (d,
J=8.8 Hz, 1H), 8.29 (d,
J=5.6 Hz, 1H), 7.34 (d,
J=2.0 Hz, 1H), 7.14 (dd,
J=8.8, 2.4 Hz, 1H), 4.59 (t,
J=6.4 Hz, 2H), 4.34 (dd,
J=10.0
, 3.6 Hz, 1H), 4.17 (dd,
J=10.0
, 6.4 Hz, 1H), 3.98 (t,
J=6.0 Hz, 2H), 3.63-3.53 (m, 1H), 1.92-1.80 (m, 1H), 1.66 - 1.59 (m, 2H), 1.06 - 1.03
(m, 6H).
Example 45
(S)-8-(2-amino-4-methylpentyloxy)-6-(2,2,2-trifluoroethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0327]

Part A. 4-(4-chloro-2-fluorophenyl)-N-(2,2,2-trifluoroethyl)nicotinamide
[0328] To stirred solution of 4-(4-chloro-2-fluorophenyl)nicotinic acid (300 mg, 1.192 mmol),
prepared as described in Example 2, Part A, in anhydrous DMF (2 mL) under nitrogen
was added HOBT (365 mg, 2.384 mmol), DIEA (0.927 mL, 4.77 mmol) and EDC (343 mg, 1.788
mmol). The reaction mixture was cooled to 0 °C and treated with 2,2,2-trifluoroethanamine
(236 mg, 2.384 mmol) drop wise and warmed to RT and allowed to stir for 12 h. The
reaction mixture was diluted with water (20 mL) and extracted with ethyl acetate (2
x 50 mL). The combined organic layers were dried over sodium sulphate and concentrated
under reduced pressure to afford 4-(4-chloro-2-fluorophenyl)-
N-(2,2,2-trifluoroethyl)nicotinamide (200 mg, 0.601 mmol, 50% crude yield) as a yellow
solid. LC/MS (ESI)
m/
e 333.2, [(M+H)
+, calcd for C
14H
10ClF
4N
2O, 333.0]; LC/MS retention time (method A):
tR = 1.66 min.

Part B. 8-chloro-6-(2,2,2-trifluoroethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0329] Prepared as described in Example 2, Part C to afford 8-chloro-6-(2,2,2-trifluoroethyl)benzo[
c][2,7]naphthyridin-5(
6H)-one (150 mg, 0.480 mmol, 80 % yield) LC/MS (ESI)
m/
e 313.1, [(M+H)
+, calcd for C
14H
9ClF
9N
2O, 313.0]; LC/MS retention time (method D):
tR = 0.95 min.

Part C. (S)-tert-butyl (4-methyl-1-((5-oxo-6-(2,2,2-trifluoroethyl)-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0330] Prepared as described in Example 16, Part H to afford
(S)-tert-butyl (4-methyl-1-((5-oxo-6-(2,2,2-trifluoroethyl)-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (100 mg, 0.203 mmol, 42% yield)
as a brown solid. LC/MS (ESI)
m/
e 494.5, [(M+H)
+, calcd for C
25H
31F
3N
3O
4 494.2]; LC/MS retention time (method C):
tR = 2.17 min.

Part D. (S)-8-((2-amino-4-methylpentyl)oxy)-6-(2,2,2-trifluoroethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0331] Prepared as described in Example 2, Part E to afford
(S)-8-((2-amino-4-methylpentyl)oxy)- 6-(2,2,2-trif[uoroethyl)benzo[
c][2,7]naphthyridin-5(
6H)-one (25 mg, 0.061 mmol, 30% yield), white solid. LC/MS (ESI)
m/
e 394.2, [(M+H)
+, calcd for C
20H
20F
3NO
2, 394.2]; LC/MS retention time (method C):
tR = 1.78 min. HPLC retention time (method A):
tR = 5.26 min; HPLC retention time (method B):
tR = 5.60 min.
1H NMR (400 MHz,
MeOD) δ 9.49 (s, 1H), 8.81 (d,
J=5.6 Hz, 1H), 8.46 (d,
J=8.8 Hz, 1H), 8.28 (d,
J=5.6 Hz, 1H), 7.23 (br s, 1H), 7.15 (dd,
J=8.8, 2.0 Hz, 1H), 5.32 (dd, J
=8.8, 6.4 Hz, 2H), 4.21 (dd,
J=9.2, 3.6 Hz, 1H), 4.03 (dd,
J=9.2, 7.2 Hz, 1H), 3.40-3.33 (m, 1H), 1.92-1.80 (quin,
J=6.8, 1H), 1.52 - 1.46 (m, 2H), 1.02 (d,
J=6.4 Hz, 3H), 1.00 (d,
J=6.4 Hz, 3H).
Example 46
(S)-8-(2-amino-4-methylpentyloxy)-9-ethyl-6-methylbenzo[c][2,7]na*phthyridin-5(6H)-one
[0332]

Part A. (S)-tertbutyl (4-methyl-1-((6-methyl-5-oxo-9-vinyl-5,6 dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2- yl)carbamate
[0333] A mixture of
(S)-tert-butyl (1-((9-bromo-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.250 g, 0.496 mmol) (prepared
as described in Example 3, Part B) 2,4,6-trivinylcyclotriboroxane pyridine complex
(0.239 g, 0.991 mmol), Na
2CO
3 (0.158 g, 1.487 mmol) and Pd(PPh
3)
4 (0.029 g, 0.025 mmol) in toluene (1mL) water (0.1 mL), and ethanol (0.3 mL) was purged
with nitrogen gas and heated at 90 °C for 16 h. After cooling, the reaction mixture
was transferred to separatory funnel containing water (10 mL) and extracted with ethyl
acetate (3 x 10 mL). The combined organic layers were dried over sodium sulphate and
concentrated under reduced pressure. The residue was purified by column chromatography
on silica gel (60% ethyl acetate: petroleum ether) to afford a
(S)-tert-butyl(4-methyl-1-((6-methyl-5-oxo-9-vinyl-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (0.150 g, 0.166 mmol, 34% yield)
as a yellow solid. LC/MS (ESI)
m/
e 452.4, [(M+H)
+, calcd for C
26H
34N
3O
4, 452.2]; LC/MS retention time (method D):
tR = 0.95 min.

Part B. (S)-tert-butyl (1-((9-ethyl-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan
2-yl)carbamate
[0334] A mixture of
(S)-tert-butyl (4-methyl-1-((6-methyl-5-oxo-9-vinyl-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (0.15 g, 0.332 mmol) and palladium
on carbon (0.075 g, 0.070 mmol) in MeOH (3 mL) and ethyl acetate (3 mL) was stirred
at RT under a balloon of hydrogen gas for 24 h. The reaction mixture was filtered
through diatomaceous earth (Celite
®) and the filtrate was concentrated under reduced pressure. The residue was purified
by prep TLC (60 % ethyl acetate and petroleum ether) to afford
(S)-tert-butyl (1-((9-ethyl-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan
2-yl)carbamate (0.11 g, 0.133 mmol, 40 % yield) as a yellow semi solid. LC/MS (ESI)
m/
e 454.4, [(M+H)
+, calcd for C
26H
36N
3O
4, 454.3]; LC/MS retention time (method D):
tR = 0.96 min.

Part C. (S)-8-((2-amino-4-methylpentyl)oxy)-9-ethyl-6-methylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0335] Prepared as described in Example 2, Part E to afford the title compound (55 mg, 0.155
mmol, 64% yield) as a yellow solid. LC/MS (ESI)
m/
e 354.2, [(M+H)
+, calcd for C
21H
28N
3O
2, 354.2]; LC/MS retention time (method C):
tR = 1.94 min. HPLC retention time (method A):
tR = 8.76 min; HPLC retention time (method B):
tR = 5.19 min.
1H NMR (400 MHz,
MeOD) δ 9.52 (s, 1H), 8.81 (d,
J=6.0 Hz, 1H), 8.51 (d,
J=8.8 Hz, 1H), 8.33 (s, 1H), 7.11 (s, 1H), 4.52 (m, 1H), 4.36 (m, 1H), 3.86 (s, 3H),
3.76-3.84 (m, 1H), 2.86-2.93 (m, 2H), 1.81-1.90 (m, 2H), 1.63 - 1.81 (m, 1H), 1.35
(m, 3H), 1.05 (m, 6H).
Example 47
(S)-8-(2-amino-4-methylpentyloxy)-9-isopropyl-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0336]

Part A. (S)-tert-butyl (4-methyl-1-((6-methyl-5-oxo-9-(prop-1-en-2-yl)-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0337] Prepared as described in Example 46, Parts A and B to afford
(S)-tert-butyl (4-methyl-1-((6-methyl-5-oxo-9-(prop-1-en-2-yl)-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (100 mg, 0.215 mmol, 90% yield)
as a solid. LC/MS (ESI)
m/
e 466.4, [(M+H)
+, calcd for C
27H
36N
3O
4, 466.3]; LC/MS retention time (method C):
tR = 2.22 min.

Part B.(S)-tert-butyl (1-((9-isopropyl-6-methyl-5-oxo-5,6 dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0338] A mixture of
(S)-tert-butyl (4-methyl-1-((6-methyl-5-oxo-9-(prop-1-en-2-yl)-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (0.1 g, 0.215 mmol) and palladium
on carbon (0.07 g, 0.066 mmol) in MeOH (3 mL) and ethyl acetate (3 mL) was stirred
at RT under a balloon of hydrogen gas for 24 h. The reaction mixture was filtered
through diatomaceous earth (Celite
®) and the filtrate was concentrated under reduced pressure to afford
(S)-tert-butyl (1-((9-isopropyl-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.04 g, 2.464 mmol, 1%
yield) as a brown oil, which was carried on without further purification. LC/MS (ESI)
m/
e 468.4, [(M+H)
+, calcd for C
27H
38N
3O
4, 468.3]; LC/MS retention time (method D):
tR = 1.00 min.

Part C. (S)-8-(2-amino-4-methylpentyloxy)-9-isopropyl-6-methylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0339] Prepared as described in Example 2, Part E to afford the title product (12.05 mg,
0.033 mmol, 99% (purity) as a yellow solid. LC/MS (ESI)
m/
e 368.2, [(M+H)
+, calcd for C
22H
30N
3O
3, 368.2]; LC/MS retention time (method C):
tR = 1.97 min. HPLC retention time (method A):
tR = 7.28 min; HPLC retention time (method B):
tR = 10.15 min.
1HNMR (400 MHz,
MeOD) δ ppm 9.54 (s, 1H), 8.82 (d,
J=6.0 Hz, 1H), 8.60 (d,
J=8.8 Hz, 1H), 8.36 (s, 1H), 7.12 (s, 1H), 4.52 (m, 1H), 4.41 (m, 1H), 3.86 (s, 3H),
3.74-3.84 (m, 1H), 3.61 (m, 1H), 1.80-1.90 (m, 2H), 1.64 - 1.81 (m, 1H), 1.35-1.43
(m, 6H), 1.02-1.11 (m, 6H).
Example 48
(S)-8-(2-amino-4-methylpentyloxy)-6-methyl-9-(oxazol-5-yl)benzo[c][2,7]naphthyridin-5(6H)-one
[0340]

Part A. (S)-tert-butyl 1-(9-formyl-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0341] A mixture of (
S)-
tert-butyl (4-methyl-1-((6-methyl-5-oxo-9-vinyl-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (300 mg, 0.664 mmol) (prepared as
described in Example 46, Part A) osmium tetroxide (2.5% in 2-methyl-2-propanol) (4.17
µl, 0.013 mmol), and 2,6-dimethylpyridine (0.155 mL, 1.329 mmol) in 1,4-dioxane (5
mL) and water (2 mL), cooled to 0°C, was stirred for 15 min. Sodium metaperiodate
(568 mg, 2.66 mmol) was added and the reaction was warmed to room temperature and
stirred for 2 h. The reaction mixture was filtered through diatomaceous earth (Celite
®), eluting with EtOAc. The EtOAc layer was washed with saturated aqueous NaHCO
3, H
2O, then brine. The organic layer was dried with Na
2SO
4, filtered and concentrated under reduced pressure. The residue was purified by silica
gel chromatography (EtOAc/petroleum ether) to afford
(S)-tert-butyl (1-((9-formyl-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (160 mg, 0.353 mmol, 53
% yield) as a gummy solid. LC/MS (ESI)
m/
e 454.1, [(M+H)
+, calcd for C
25H
12N
3O
5, 454.2].

Part B. (S)-tert-butyl (4-methyl-1-((6-methyl-9-(oxazol-5-yl)-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0342] A mixture of
(S)-tert-butyl (1-((9-formyl-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (100 mg, 0.220 mmol), K
2CO
3 (33.5 mg, 0.243 mmol) and TOSMIC (47.4 mg, 0.243 mmol) in MeOH (5 mL) was heated
at 60 °C for 2 h. After cooling, the MeOH was removed under reduced pressure and residue
was taken up in ethyl acetate. The organic layer was washed with H
2O, followed by saturated NaHCO
3, dried over Na
2SO
4 and concentrated under reduced pressure to afford
(S)-tert-butyl (4-ethyl-1-((6-methyl-9-(oxazol-5-yl)-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (50 mg, 0.054 mmol, 24% crude yield)
as a gum. The material was carried on without further purification. LC/MS (ESI)
m/
e 493.4, [(M+H)
+, calcd for C
27H
33N
4O
5, 493.6]; LC/MS retention time (method E):
tR = 1.08 min.

Part C. (S)-8-(2-amino-4-methylpentyloxy)-6-methyl-9-(oxazol-5-yl)benzo[c][2,7]naphthyridin-5(6H)-one
[0343] Prepared as described in Example 2, Part E to afford
(S)-8-(2-amino-4-methylpentyloxy)-6-methyl-9-(oxazol-5-yl)benzo[
c][2,7]naphthyridin-5(
6H)-one (15 mg, 0.038 mmol, 29% yield) as a yellow solid. LC/MS (ESI)
m/
e 393.2, [(M+H)
+, calcd for C
22H
25N
4O
3, 393.2]; LC/MS retention time (method C):
tR = 1.70 min. HPLC retention time (method A):
tR = 8.89 min; HPLC retention time (method B):
tR = 9.12 min.
1H NMR (400 MHz, METHANOL-
d4) δ ppm 1.07 - 1.13 (m, 6 H) 1.75 (d,
J=6.78 Hz, 1 H) 1.81 - 1.93 (m, 2 H) 3.91 (s, 3 H) 3.94 - 4.00 (m, 1 H) 4.55 (dd,
J=11.04
, 6.53 Hz, 1 H) 4.67 (dd,
J=10.92, 3.39 Hz, 1 H) 7.30 (s, 1 H) 7.71 (s, 1 H) 8.43 (s, 1 H) 8.55 (d,
J=5.52 Hz, 1 H) 8.90 (s, 2 H) 9.59 (s, 1 H).
Example 49
(S)-8-(2-amino-4-methylpentyloxy)-9-bromo-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0344]

Part A. 4-(4-chloro-2-fluorophenyl)-2-methylnicotinamide
[0345] 4-(4-Chloro-2-fluorophenyl)-2-methylnicotinic acid (9 g, 33.9 mmol) (previous described
in Example 16, Part E) was taken in DCM (50 mL) and cooled to 0 °C. The solution was
treated with oxalyl chloride (14.83 mL, 169 mmol) followed by slow addition of DMF
(1 mL). The mixture was heated at 40°C for 3 h. After cooling, the volatiles were
removed under reduced pressure. The residue taken up in DCM (25 mL) was cooled to
0°C, and TEA (22.08 mL, 158 mmol) and ammonium chloride (16.94 g, 317 mmol) were added
slowly. After stirring at room temperature for 1 h, the reaction mixture was washed
with saturated aqueous NaHCO3 (10 mL), water (10 mL), and brine (10 mL). The organic
layer was separated and dried with Na
2SO
4 to afford the 4-(4-chloro-2-fluorophenyl)-2-methylnicotinamide (3.5 g, 13.2 mmol,
42% crude yield) as a brown solid. The material was carried forward without further
purification. LC/MS (ESI) m/e 264.4 [(M)
+, calcd for C
13H
10ClFN
2O 264.0] LC/MS retention time (method C):
tR = 1.58 min.

Part B. 8-chloro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0346] Prepared as described in Example 2, Part C to afford 8-chloro-4-methylbenzo[c][2,7]naphthyridin-5(
6H)-one (800 m g, 3.14 mmol, 24% yield, 96% purity) as a yellow solid. LC/MS (ESI) m/e
245.1 [(M+H)
+, calcd for C
13H
10ClN
2O 245.04] LC/MS retention time (method D):
tR = 0.52 min.

Part C. 8-chloro-6-(4-methoxybenzyl)-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0347] Prepared as described in Example 17, Part G to afford 8-chloro-6-(4-methoxybenzyl)-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (710 m g, 1.362 mmol, 56% yield) as a brown gum. LC/MS (ESI) m/e 365.1 [(M+H)
+, calcd for C
21H
18ClN
2O
2 365.1] LC/MS retention time (method D):
tR = 0.8 min.

Part D. (S)-tert-butyl 1-(6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0348] Prepared as described in Example 16, Part H to afford
(S)-tert-butyll-(6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate (130 mg, 0.21 mmol, 31 %
yield, 88% purity) as a brown gum. LC/MS (ESI) m/e 546.2 [(M+H)
+, calcd for C
32H
40FN
3O
5 546.3] LC/MS retention time (method D):
tR = 0.94 min.

Part E. (S)-tert-butyl 1-(9-bromo-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0349] Prepared as described in Example 3, Part A to afford
(S)-
tert-butyl 1-(9-bromo-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate (140 mg, 0.146 mmol, 61 %
yield, 65% purity) as an orange red solid. LC/MS (ESI) m/e 624.2 [(M+H)
+, calcd for C
32H
39BrN
3O
5 624.2] LC/MS retention time (method D):
tR = 0.98 min.

Part F. (S)-tert-butyl 1-(9-bromo-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
Part G. (S)-8-(2-amino-4-methylpentyloxy)-9-bromo-4-methylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0351] Prepared as described in Example 2, Part E to afford
(S)-8-(2-amino-4-methylpentyloxy)-9-bromo-4-methylbenzo[c][2,7]naphthyridin-5(
6H)-one (12 mg, 0.029 mmol, 35 % yield, 98% purity) as a off-white solid. LC/MS (ESI)
m/e 402.0 [(M)
-, calcd for C
19H
21BrN
3O
2 402.1] LC/MS retention time (method C):
tR = 2.19 min. HPLC retention time (method A): t
R = 8.52 min and HPLC retention time (method B): t
R = 9.02 min.
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.67 (s, 1H), 8.64 (d,
J=6.0 Hz, 1H), 8.30 (d,
J=6.0 Hz, 1H), 6.98 (s, 1H), 4.85 - 4.43 (m, 1H), 4.31 - 4.27 (m, 1H), 3.82 - 3.80
(m, 1H), 3.13 (s, 3H), 1.88 - 1.80 (m, 2H), 1.76 - 1.71 (m, 1H), 1.09 (d,
J=6.4 Hz, 3H), 1.07 (d,
J=6.4 Hz, 3H).
Example 50
(S)-8-((2-amino-4-methylpentyl)oxy)-4-((4-methoxybenzyl)amino)-6-methylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0352]

[0353] Prepared as described in Example 17, Part H and Example 2, Part E to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-4-((4-methoxybenzyl)amino)-6-methylbenzo[c][2,7]naphthyridin-5(
6H)-one hydrochloride (19 mg, 0.038 mmol, 26 % yield) as a pale yellow solid. LC/MS
(ESI)
m/
e 461 [(M+H)
+, calcd for C
27H
33N
4O
3, 461.25]; LC/MS retention time (method B):
tR = 1.42 min. HPLC retention time (method A):
tR = 11.09 min; HPLC retention time (method B):
tR = 12.68 min.
1H NMR (400 MHz,
DMSO-d6) δ 10.09 (br. s. 1 H), 8.40 (d,
J=8.8 Hz, 1H), 8.24 (d,
J=6.0 Hz, 1H), 8.07 (s, 3H), 7.45 (d,
J=6.0 Hz, 1H), 7.33 (d,
J=8.4 Hz, 2H), 7.07 - 7.06 (m, 2H), 6.95-6.91 (m, 2H), 4.67 (d,
J=5.2 Hz, 1H), 4.38 (dd,
J=10.4, 3.2 Hz, 2H), 4.21 (dd,
J=10.8, 6.8 Hz, 1H), 3.75 (s, 3H), 3.68 (s, 3H), 3.62 (br s, 1H), 1.80 (quin,
J=6.8, 1H), 1.59-1.55 (m, H), 0.95 (d,
J=6.4 Hz, 3H), 0.94 (d,
J=6.4 Hz, 3H).
Example 51
(S)-8-((2-amino-4-methylpentyl)oxy)-9-(4-fluorophenyl)-6 methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0354]

Part A. (S)-tert-butyl (1-((9-(4-fluorophenyl)-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0355] (
S)-
tert-Butyl (1-((9-bromo-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
(150 mg, 0.297 mmol) (prepared as described in Example 3, Part A) 4-fluorophenylboronic
acid (49.9 mg, 0.357 mmol), Cs
2CO
3 (291 mg, 0.892 mmol) and PdCl
2(dppf)-CH
2Cl
2 adduct (12.14 mg, 0.015 mmol) in 1,4-dioxane (8 mL) and water (0.4 mL) was degassed
with nitrogen gas for 5 min then heated at 80 °C overnight. The reaction mixture was
cooled to room temperature and concentrated under reduced pressure. The residue was
taken up in dichloromethane (10 mL) and water (8 mL). The organic layer was separated,
dried with sodium sulfate, filtered and concentrated under reduced pressure to afford
(S)-tert-butyl (1-((9-(4-fluorophenyl)-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.13 g, 0.09 mmol, 31%
yield) as a brown gum. The materialwas carried forward without further pruification.
LC/MS, (ESI)
m/
z 520.4 [(M+H)
+, calcd for C
30H
35FN
3O
4 520.25]; LC/MS retention time (method D):
tR = 1.08 min.

Part B. (S)-8-((2-amino-4-methylpentyl)oxy)-9-(4-fluorophenyl)-6 methylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0356] Prepared as described in Example 2, Part E to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-9-(4-fluorophenyl)-6 methylbenzo[c][2,7]naphthyridin-5(
6H)-one (19 mg, 0.043 mmol, 47% yield) as a pale yellow solid. LC/MS, (ESI)
m/
z 420.0 [(M+H)
+, calcd for C
25H
27FN
3O
2, 420.3]; LC/MS retention time (method C'):
tR = 1.61 min.
1H NMR (400MHz, METHANOL-
d4) δ ppm 9.40 (s, 1H), 8.69 (m, 1H), 8.24 (s, 1H), 8.18 (m, 1H), 7.62 (m, 2H), 7.22
(m, 2H), 7.04 (s, 1H), 4.16 (m, 1H), 3.98 (m, 1H), 3.78 (s, 3H), 3.20 (m, 1H), 1.78
(m, 1H), 1.35 (m, 2H), 0.90-0.98 (m, 6H).
Example 52
(S)-4-amino-8-(2-amino-4-methylpentyloxy)-9-fluoro-6-methylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0357]

Part A. tert-butyl 4-(4-chloro-2,5-difluorophenyl)-3-formylpyridin-2-ylcarbamate
[0358] Prepared as described in Example 17, Part C by Suzuki coupling between 2-(4-chloro-2,5-difluorophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane)
preparation described in Example 14, Part A) and
tert-butyl 4-chloro-3-formylpyridin-2-ylcarbamate (Preparation described in Example 17,
Part B) to afford
tert-butyl 4-(4-chloro-2,5-difluorophenyl)-3-formylpyridin-2-ylcarbamate (3.7 g, 8.91
mmol, 76% yield) as a yellow solid. LC/MS (ESI) m/e 367.1 [(M)
-, calcd for C
17H
16ClF
2N
2O
3 367.1] LC/MS retention time (method E):
tR = 1.07 min.

Part B: 4-(tert-butoxycarbonylamino)-8-chloro-9-fluoro-6-methylbenzo[c][2,7]naphthyridin-6-ium
[0359] To a stirred solution of
tert-butyl (4-(4-chloro-2,5-difluorophenyl)-3-formylpyridin-2-yl)carbamate (2.6 g, 6.26
mmol) in DCM (10 mL) at 0 °C was added dropwise methanamine (2M in MeOH) (75 mL, 6.26
mmol) and the reaction mixture was stirred at rt for 18 hours. The reaction mixture
concentrated under reduced pressure. The residue was triturated with EtOAc/ hexane
and the solid obtained was collected by vacuum filtration to yield 4-((
tert-butoxycarbonyl)amino)-8-chloro-9-fluoro-6-methylbenzo[c][2,7]naphthyridin-6-ium (2.7
g, 2.399 mmol, 38% yield) as a yellow solid. Sample was taken to the next step without
further purification.LC/MS (ESI) m/e 362.2 [(M+H)
+, calcd for C
18H
18ClFN
3O
2 362.1] LC/MS retention time (method E):
tR = 0.66 min.

Part C: 8-chloro-9-fluoro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-4-ylcarbamic
acid
[0360] To a stirred solution of 4-((
tert-butoxycarbonyl)amino)-8-chloro-9-fluoro-6-methylbenzo[c][2,7]naphthyridin-6-ium (2.6
g, 2.310 mmol) in a mixture of DCM (10 mL) and water (50 mL) was added NaOH (0.370
g, 9.24 mmol) in three portions, followed by the addition of KMnO
4 (1.461 g, 9.24 mmol) in five protions and the reaction was heated to 90 °C for 5
h. After cooling, the solvent was removed under reduced pressure. The reidue was taken
up in EtOAc (50 mL) and MeOH (50 mL) and stirred for 10 min. The reaction mixture
was then passed through diatomaceous earth (Celite
®), eluting with EtOAc. The filtrate was concentrated to yield (8-chloro-9-fluoro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-4-yl)carbamic
acid (2.35 g, 2.082 mmol, 90 % crude yield) as a yellow solid which was taken to the
next step without purification. LC/MS (ESI) m/e 322.1 [(M+H)
+, calcd for C
14H
10ClFN
3O
3 322.0] LC/MS retention time (method E):
tR = 1.05 min.

Part D: 8-chloro-9-fluoro-4-(4-methoxybenzylamino)-6-methylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0361] Prepared as described in Example 17, Part F to give the 4-amino-8-chloro-9-fluoro-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one which was then protected with PMB as per procedure described in Example 17,
Part G to afford the title product (0.45 g, 0.755 mmol, 17 % yield) as a yellow oil.
LC/MS (ESI) m/e 398.2 [(M+H)
+, calcd for C
21H
18ClFN
3O
2 398.1] LC/MS retention time (method E):
tR = 1.23 min.

Part E: (S)-tert-butyl 1-(9-fluoro-4-(4-methoxybenzylamino)-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0362] Prepared as described in Example 16, Part H to afford the title product (910 mg,
0.405 mmol, 54% yield) as a yellow oil. LC/MS (ESI) m/e 579.5 [(M+H)
+, calcd for C
12H
40FN
4O
5 579.3] LC/MS retention time (method E):
tR = 1.37 min.

Part F: (S)-4-amino-8-(2-amino-4-methylpentyloxy)-9-fluoro-6-methylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0363] Prepared as described in Example 2, Part E to afford the title product (27 mg, 0.045
mmol, 11 % yield) pale yellow solid in the form of TFA salt. LC/MS (ESI) m/e 359.2
[(M+H)
+, calcd for C
19H
24FN
4O
2 359.2] LC/MS retention time (method C):
tR = 1.53 min. HPLC retention time (method A): t
R = 8.01 min and HPLC retention time (method B):
tR = 9.13 min.
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.33 (d,
J=12.0 Hz, 1H), 8.02 (d,
J=7.0 Hz, 1H), 7.67 (d,
J=7.3 Hz, 1H), 7.34 (d,
J=7.3 Hz, 1H), 4.60 (dd,
J=10.7, 3.1 Hz, 1H), 4.46 (dd,
J=10.8, 6.0 Hz, 1H), 3.87 (s, 3H), 3.86 - 3.78 (m, 1H), 1.95 - 1.64 (m, 3H), 1.08 (d,
J=4.3 Hz, 3H), 1.07 (d,
J=4.3 Hz, 3H).
Example 53
(S)-8-(2-amino-3-isopropoxypropoxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0364]

Part A. (S)-methyl 2-(((benzyloxy)carbonyl)amino)-3-isopropoxypropanoate
Part B. (R)-benzyl (1-hydroxy-3-isopropoxypropan-2-yl)carbamate
[0366] (S)-Methyl 2-(((benzyloxy)carbonyl)amino)-3-isopropoxypropanoate (0.02 g, 0.068 mmol)
was taken in 2-propanol (4 mL) and then NaBH
4 (7.69 mg, 0.203 mmol) was added and the mixture stirred for overnight at 50 °C. After
cooling to 0 °C, the mixture was quenched with 1N HCl and then extracted with diethyl
ether (10 mL). The diethyl ether layer was collected and concentrated under reduced
pressure to afford (R)-benzyl (1-hydroxy-3 isopropoxypropan-2-yl)carbamate) (14 mg,
0.058 mmol, 86% crude yield) as colorless oil. The product was carried on without
further purification.
1H NMR (400 MHz,
MeOD) δ 7.31-7.48 (m, 5H), 5.12 (s, 1H), 4.81 (bs, 1H), 3.41-3.91 (m, 6H), 1.12-1.26 (m,
6H).

[0367] Part C:
(S)-benzyl (1-isopropoxy-3-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate
[0368] Prepared as described in Example 16, Part H to afford the title product
(S)-benzyl (1-isopropoxy-3-((6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate
(220 mg, 0.130 mmol, 10% yield) as a light yellow solid. LC/MS (ESI)
m/
e 476.4, [(M+H)
+, calcd for C
27H
30N
3O
5, 476.2]; LC/MS retention time (method E):
tR = 1.04 min.

Part D: (S)-8-(2-amino-3-isopropoxypropoxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0369] A solution of (
S)-benzyl (1-isopropoxy-3-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate (220 mg, 0.130 mmol) in MeOH (12
mL) was degassed with N
2 for 5 min. Pd/C (68.9 mg, 0.065 mmol) was added and the mixture stirred under a balloon
of H
2 for 12h. The reaction mixture was filtered through diatomaceous earth (Celite
®), eluting with methanol and the filtrate was concentrated under reduced pressure.
The rsidue was purified by reverse phase HPLC (10 MM ammonium acetate in water/AcCN)
to afford (
S)-8-(2-amino-3-isopropoxypropoxy)-6-methylbenzo[c][2,7]naphthyridin-5(
6H)-one (90 mg, 0.108 mmol, 83 % yield) as an off-white solid. LC/MS (ESI)
m/
e 342.2, [(M+H)
+, calcd for C
19H
24N
3O
3, 342.2]; LC/MS retention time (method C):
tR = 1.50 min. HPLC retention time (method A):
tR = 7.20 min; HPLC retention time (method B):
tR = 8.00 min.
1H NMR (400 MHz,
MeOD) δ ppm 9.54 (s, 1H), 8.23 (d,
J=4.4 Hz, 1H), 8.52 (d,
J=8.8 Hz, 1H), 8.44 (d,
J=6.0 Hz, 1H), 7.20 (s, 1H), 7.18 (d,
J=6.0 Hz, 1H), 4.52 (dd,
J=10.4, 3.6 Hz, 1H), 4.43 (dd,
J=10.4, 6.8 Hz, 1H), 3.88-3.75 (m, 7H), 1.26 (d,
J=6.4 Hz, 3H), 1.25 (d,
J=6.4 Hz, 3H).
Example 54
(S)-6-methyl-8-((4-methyl-2-(methylamino)pentyl)oxy)benzo[c][2,7]naphthyridin-5(6H)-one
[0370]

Part A. (S)-tert-butyl methyl(4-methyl-1-(6-methyl-5-oxo-5,6-dihydrobenzo[c] [2,7]naphthyridin-8-yloxy)pentan-2-yl)carbamate
[0371] To a solution of
(S)-tert-butyl (4-methyl-1-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (200 mg, 0.470 mmol) (Preparation
description in Example 2, Part D) in THF (4 mL) at 0 °C was added NaH (37.6 mg, 0.940
mmol). The reaction was stirred at 0 °C for 30 min then MeI (0.044 mL, 0.705 mmol)
was added. The reaction mixture was then stirred at 0 °C for 16 h. The reaction mixture
was quenched with ice cold water (50 mL) and extracted with ethyl acetate (3x30 mL).
The combined organic layers and washed with brine (1x50 mL), dried over Na
2SO
4, filtered and concentrated under reduced pressure. The crude product was purified
by silica gel chromatography using petroleum ether: ethyl acetate mobile phase to
afford (
S)-
tert-butyl methyl(4-methyl-1-(6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)pentan-2-yl)carbamate (180 mg, 0.409 mmol, 87% yield) as
a yellow solid. LC/MS (ESI)
m/
e 440.4, [(M+H)
+, calcd for C
25H
34N
3O
4, 440.3]; LC/MS retention time (method I):
tR = 2.4 min.

Part B: (S)-6-methyl-8-((4-methyl-2-(methylamino)pentyl)oxy)benzo[c][2,7]naphthyridin-5(6H)-one
[0372] To the solution of (
S)-
tert-butyl methyl(4-methyl-1-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (180 mg, 0.078 mmol) in dichloromethane
(4 mL) cooled to 0 °C was added HCl in ether (4 mL, 4.00 mmol) slowly over a period
of 1 min. The reaction mixture was stirred at 0 °C for 5 min then warmed to room temperature
and stirred for 4 h. The volatiles were then removed under reduced pressure. The residue
was purified via reverse phase HPLC (0.1% TFA in water:acetonitrile) to afford (
S)-6-methyl-8-((4-methyl-2-(methylamino)pentyl)oxy)benzo[
c][2,7]naphthyridin-5(6
H)-one (15 mg, 0.025 mmol, 32% yield) as a yellow solid. LC/MS (ESI)
m/
e 340.2, [(M+H)
+, calcd for C
20H
26N
3O
2, 340.2]; LC/MS retention time (method I):
tR = 1.6 min. HPLC retention time (method A):
tR = 7.59 min; HPLC retention time (method B):
tR = 8.08 min.
1H NMR (400MHz, METHANOL-d
4) δ ppm 9.54 (s, 1H), 8.83 (d,
J=5.8 Hz, 1H), 8.53 (d,
J=8.8 Hz, 1H), 8.46 (d,
J=6.0 Hz, 1H), 7.27 - 7.16 (m, 2H), 4.57 (dd,
J=11.3, 3.0 Hz, 1H), 4.44 (dd,
J=11.3
, 5.3 Hz, 1H), 3.84 (s, 3H), 3.78 - 3.68 (m, 1H), 2.84 (s, 3H), 1.95 - 1.78 (m, 2H),
1.75 - 1.61 (m, 1H), 1.08 (d,
J=6.5 Hz, 6H).
Example 55
(S)-8-((2-amino-4,4-difluoropentyl)oxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0373]

Part A: (S)-methyl 2-((tert-butoxycarbonyl)amino)-4-methylpent-4-enoate
[0374] To a solution of (
S)-2-((
tert-butoxycarbonyl)amino)-4-methylpent-4-enoic acid (550 mg, 2.399 mmol) in tetrahydrofuran
(11 mL) at 0 °C, was added TMS-diazomethane (4.80 mL, 4.80 mmol) dropwise over 5 min.
The reaction mixture was then stirred at 0 °C for 15 min. After gradually warmed to
room temperature, the mixture was stirred for 16h. The reaction mixture was evaporated
to dryness to afford (
S)-methyl 2-((
tert-butoxycarbonyl)amino)-4-methylpent-4-enoate (580 mg, 2.386 mmol, 99% crude yield)
as a dark yellow oil which was taken to the next step without purification.
1H NMR (400 MHz,
CDCl3): δ ppm 4.91 (s, 1H), 4.85 (s, 1H), 4.75 (s, 1H), 4.38 (q,
J= 16.00 Hz, 1H), 3.73 (s, 3H), 2.33-2.53 (m, 2H), 1.71 (s, 3H), 1.43 (s, 9H).

Part B: (S)-methyl 2-((tert-butoxycarbonyl)amino)-4-oxopentanoate
[0375] To a solution of (
S)-methyl 2-((
tert-butoxycarbonyl)amino)-4-methylpent-4-enoate (500 mg, 2.055 mmol) in a solvent mixture
of 1,4-dioxane (10 mL) and water (2.5 mL) at 0 °C, was added 2,6-lutidine (0.479 mL,
4.11 mmol) and osmium tetroxide (2.5% in 2-methyl-2-propanol) (0.516 mL, 0.041 mmol),
followed by sodium metaperiodate (1.758 g, 8.22 mmol). The reaction mixture was stirred
at 0 °C for 15 min and warmed to room temperature and stirred for an additional 3h.
The mixture was diluted with ethyl acetate (150 mL) and washed with 10% aqueous NaHCO
3. The organic layer was separated, dried over sodium sulphate and concentrated under
reduced pressure to afford (
S)-methyl
2-((
tert-butoxycarbonyl)amino)-4-oxopentanoate (500 mg, 2.040 mmol, 100% crude yield) as a
yellow liquid. The material was caried on without further purification.
1H NMR (400 MHz, CDCl
3): δ ppm 5.48 (s, 1H), 4.51 (t,
J = 8.00 Hz, 1H), 3.75 (s, 3H), 3.23 (d,
J= 4.00 Hz, 1H), 3.17 (d,
J = 4.00 Hz, 1H), 2.18 (s, 3H), 1.46 (s, 9H).

Part C: (S)-methyl 2-((tert-butoxycarbonyl)amino)-4,4-difluoropentanoate
[0376] To (
S)-methyl 2-((
tert-butoxycarbonyl)amino)-4-oxopentanoate (300 mg, 1.223 mmol) at 0 °C, was added DAST
(M in) (323 µL, 2.446 mmol) dropwise. The reaction mixture was stirred at room temperature
for 84h. The reaction mixture was cooled to 0 °C and then quenched with aqueous 10%
NaHCO
3 solution. The resulting suspension was extracted with ethyl acetate (3 x 25 mL).
The organic layer was washed with brine (15 mL), dried over Na
2SO4, filtered, and concentrated under reduced pressure. The crude product was purified
by silica gel chromatography to afford (
S)-methyl 2-((
tert-butoxycarbonyl)amino)-4,4-difluoropentanoate (70 mg, 0.26 mmol, 19 % yield) as a
yellow oil.
1H NMR (400 MHz, CDCl
3): δ ppm 5.15 (s, 1H), 4.50 (s, 1H), 3.75 (s, 3H), 3.23 (t,
J = 8.00 Hz, 1H), 2.30-2.45 (m, 2H), 1.60 (s, 3H), 1.44 (s, 9H).

Part D: (S)-tert-butyl (4,4-difluoro-1-hydroxypentan-2-yl)carbamate
[0377] To a solution of (
S)-methyl2-((
tert-butoxycarbonyl)amino)-4,4-difluoropentanoate (70 mg, 0.262 mmol) in tetrahydrofuran
(4 mL) at -10 °C, was added Lithium aluminum hydride, 2M in THF (0.262 mL, 0.524 mmol).
The reaction mixture was stirred at -10 °C for 2h, then quenched with aqueous ammonium
chloride (5 mL) and extracted with ethyl acetate (2 x 10 mL). The combined organic
layers were washed with brine (15 mL), dried over Na
2SO
4, filtered, and concentrated under reduced pressure to afford (
S)-
tert-butyl (4,4-difluoro-1-hydroxypentan-2-yl)carbamate (38 mg, 0.159 mmol, 61 % crude
yield) as colorless oil. The materialwas carried forward without further purification.
1H NMR (400 MHz, CDCl
3): δ ppm 3.89 (d,
J = 4.00 Hz, 2H), 2.10-2.14 (m, 1H), 1.61-1.66 (m, 2H), 1.51 (s, 3H), 1.44 (s, 9H).

Part E: (S)-tert-butyl (4,4-difluoro-1-((6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0378] In a sealed tube containing 8-chloro-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (30 mg, 0.123 mmol) and (
S)-
tert-butyl (4,4-difluoro-1-hydroxypentan-2-yl)carbamate (35.2 mg, 0.147mmol) was added
toluene (3 mL). Di-
tert-butyl(2',4',6'-triisopropyl-[1,1'-biphenyl]-2-yl)phosphine (31.2 mg, 0.074 mmol)
and cesium carbonate (59.9 mg, 0.184 mmol) were added to the reaction mixture followed
by palladium (II)acetate (8.26 mg, 0.037 mmol). The reaction mixture was then heated
at 85 °C for 16 h. The reaction mixture was cooled to room temperature, diluted with
ethyl acetate and filtered through diatomaceous earth (Celite
®), eluting with ethyl acetate. The filtrate was evaporated under reduced pressure
and the crude product was purified by silica gel chromatography to afford (
S)-
tert-butyl (4,4-difluoro-1-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (12 mg, 0.027 mmol, 22% yield) as
yellow solid. LC/MS (ESI)
m/
e 448.3 [(M+H)
+, calcd for C
23H
28F
2N
3O
4 448.2]; LC/MS retention time (method E):
tR = 0.96 min.

Part F: (S)-8-((2-amino-4,4-difluoropentyl)oxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0379] To a solution of (
S)-
tert-butyl (4,4-difluoro-1-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (15 mg, 0.024 mmol) in dichloromethane
(2 mL) at 0 °C was added 4M HCl in diethyl ether (2 mL, 2.00 mmol) dropwise over a
period of 5 min. The reaction mixture was stirred at 0 °C for 5 min and warmed to
room temperature and stirred for 3h. The volatiles were removed under reduced pressure.
The residue was dissolved in water (10 mL) and washed with ethyl acetate (2 x 5 mL).
The aqueous layer was lyophilized to afford (
S)-8-((2-amino-4,4-difluoropentyl)oxy)-6-methylbenzo[
c][2,7]naphthyridin-5(6
H)-one, 2HCl (6 mg, 0.018 mmol, 72 % yield, 93% purity) as a brown sticky solid. LC/MS
(ESI)
m/
e 348.2 [(M+H)
+, calcd for C
18H
20F
2N
3O
2 348.1]; LC/MS retention time (method E):
tR = 0.56 min. HPLC retention time (method A):
tR = 6.60 min; HPLC retention time (method B):
tR = 6.53 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 9.60 (br. s., 1H), 8.88 (br. s., 1H), 8.73 (br. s., 1H), 8.60 (br. s., 1H),
7.23 (br. s., 2H), 4.63 - 4.36 (m, 2H), 4.13 - 4.06 (m, 1H), 3.84 (br. s., 3H), 2.75
- 2.40 (m, 2H), 1.78 (t,
J=18.8 Hz, 3H).
Example 56
8-((2-amino-5,5,5- trifluoropentyl)oxy)-6-methyl-5-oxo-5,6 dihydrobenzo[c] [2,7]naphthyridine-9-carbonitrile
[0380]

Part A: tert-butyl (1-((9-bromo-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-5,5,5 trifluoropentan-2-yl)carbamate
[0381] Prepared as described in Example 15, Part E and Example 3, Part A to afford the title
product
tert-butyl (1-((9-bromo-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-5,5,5 trifluoropentan-2-yl)carbamate (0.720 g, 0.807mmol,
60% yield) as a yellow solid. LC/MS (ESI)
m/
e 546.5, [(M+2H)
+, calcd for C
23H
27BrF
3N
3O
4, 546.1]; LC/MS retention time (method D):
tR = 0.90 min.

Part B: a tert-butyl (5,5,5-trifluoro-1-((6-methyl-5-oxo-9-vinyl-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0382] Prepared as described in Example 46, Part B to afford the title product
tert-butyl (5,5,5-trifluoro-1-((6-methyl-5-oxo-9-vinyl-5,6-dihydrobenzo[
c][2,7]naphthyridin-8 yl)oxy)pentan-2-yl)carbamate (0.6 g, 0.855 mmol, 75 % yield)
as a yellow solid. LC/MS (ESI)
m/
e 492.6, [(M+H)
+, calcd for C
25H
29F
3N
3O
4, 492.2]; LC/MS retention time (method D):
tR = 0.90 min.

Part C: tert-butyl (5,5,5-trifluoro-1-((9-formyl-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0383] Prepared as described in Example 55, Part B to afford the title product
tert-butyl (5,5,5-trifluoro-1-((9-formyl-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (0.081 g, 0.079 mmol, 62% yield)
as a brown solid. LC/MS (ESI)
m/
e 494.5 (M+H)
+, calcd for C
24H
27F
3N
3O
5, 494.2]; LC/MS retention time (method D):
tR = 0.85 min.

Part D: tert-butyl (1-((9-cyano-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8 yl)oxy)-5,5,5-trifluoropentan-2-yl)carbamate
[0384] Iodine (0.047 g, 0.184 mmol) was added to a stirred solution of
tert-butyl (5,5,5-trifluoro-1-((9-formyl-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (0.165g, 0.167 mmol) in aqueous
ammonia (4 mL, 48.1 mmol) and tetrahydrofuran (6 mL) at room temperature. The dark
solution became light gray after stirring for 3 h, an indication that the reaction
was complete. The reaction mixture was charged with aqueous Na2S2O3 (25 mL of 5% solution)
and extracted with ethyl acetate (3×30 mL). The combined the organic layers were dried
over sodium sulphate and concentrated under reduced pressure to afford
tert-butyl (1-((9-cyano-6-methyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-5,5,5-trifluoropentan-2-yl)carbamate (0.14 g, 0.143 mmol,
85 % crude yield) as a pale yellow solid. The material was carried forward without
further purification. LC/MS (ESI)
m/
e 491.5 (M+H)
+, calcd for C
24H
26F
3N
4O
4, 491.2]; LC/MS retention time (method D):
tR = 0.87 min.

Part E: 8-((2-amino-5,5,5- trifluoropentyl)oxy)-6-methyl-5-oxo-5,6 dihydrobenzo[c]
[2,7]naphthyridine-9-carbonitrile
[0385] Prepared as described in Example 2, Part E to afford the title product 8-((2-amino-5,5,5-
trifluoropentyl)oxy)-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carbonitrile
(0.027 g, 0.066 mmol, 34% yield) as a white solid. LC/MS (ESI)
m/
e 391.2 [(M+H)
+, calcd for C
19H
18F
3N
4O
2, 391.1] LC/MS retention time (method C):
tR = 1.61 min. HPLC retention time (method A):
tR = 8.09 min; HPLC retention time (method B):
tR = 10.36 min.
1H NMR (400MHz, METHANOL-d
4) δ ppm 9.50 (s, 1H), 8.87 - 8.78 (m, 2H), 8.31 (d,
J=5.8 Hz, 1H), 7.20 (s, 1H), 4.42 - 4.30 (m, 1H), 4.29 - 4.20 (m, 1H), 3.84 (s, 3H),
3.40 - 3.38 (m, 1H), 2.58 - 2.31 (m, 2H), 2.09 - 1.94 (m, 1H), 1.90 - 1.72 (m, 1H).
Example 57
6-methyl-8-(piperidin-2-ylmethoxy)benzo[c][2,7]naphthyridin-5(6H)-one
[0386]

Part A: tert-butyl 2-(hydroxymethyl)piperidine-1-carboxylate
[0387] To a stirred solution of piperidin-2-ylmethanol (1.5 g, 13.02 mmol) in dichloromethane
(25 mL) was added DIPEA (6.82 mL, 39.1 mmol). After stirring for 5 min Boc
2O (3.63 mL, 15.63 mmol) was added and the mixture was stirred at RT overnight. The
mixture was quenched with water and diluted with DCM (50 mL). The organic layer was
separated, dried over Na
2SO
4 and concentrated to give
tert-butyl 2-(hydroxymethyl)piperidine-1-carboxylate (2 g, 9.29 mmol, 71% crude yield)
as a colorless oil, which was taken to the next step without further purification.
1H NMR (400 MHz,
CDCl3)ppm δ 4.27-4.28 (m, 1H), 3.80-3.82 (m, 1H), 3.75-3.77 (m, 1H), 3.56-3.58 (m, 1H), 2.63
(t, J = 7.20 Hz, 1H), 1.55-1.55 (m, 5H), 1.43 (s, 9H).

Part B: tert-butyl 2-(((6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)methyl)piperidine-1-carboxylate
[0388] Prepared as described in Example 16, Part H to afford the title product (380 mg,
0.332 mmol, 41 % yield), yellow oil. LC/MS (ESI)
m/
e 424.2, [(M+H)
+, calcd for C
24H
30N
3O
4, 424.2]; LC/MS retention time (method I):
tR = 2.29 min.

Part B: 6-methyl-8-(piperidin-2-ylmethoxy)benzo[c][2,7]naphthyridin-5(6H)-one
[0389] Prepared as described in Example 2, Part E to afford the title compound (30 mg,0.092
mmol, 53 % yield) as a pale yellow mono TFA salt. LC/MS (ESI)
m/
e 324.2 [(M+H)
+, calcd for C
19H
22N
3O
2 324.2]; LC/MS retention time (method F):
tR = 1.23 min. HPLC retention time (method A):
tR = 5.95 min; HPLC retention time (method B):
tR = 6.87 min.
1H NMR (400MHz, METHANOL-d
4) δ ppm 9.52 (s, 1H), 8.82 (d,
J=6.0 Hz, 1H), 8.51 (d,
J=9.3 Hz, 1H), 8.42 (d,
J=5.8 Hz, 1H), 7.25 - 7.15 (m, 2H), 4.49 (dd,
J=10.5, 3.5 Hz, 1H), 4.30 (dd,
J=10.8, 7.3 Hz, 1H), 3.83 (s, 3H), 3.70 (td,
J=7.5, 3.6 Hz, 1H), 3.56 - 3.45 (m, 1H), 3.21 - 3.07 (m, 1H), 2.19 - 1.95 (m, 3H),
1.88 - 1.64 (m, 3H).
Example 58 and Example 59
(S)-tert-butyl (2,4-dimethyl-1-((6-methyl-5-oxo-5,6 dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate and (R)-tert-butyl (2,4-dimethyl-1-((6-methyl-5-oxo-5,6 dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0390]

Part A: tert-butyl (2,4-dimethyl-1-((6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0391] Synthesis of 8-chloro-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one was described in example 2, Part C. 8-chloro-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.15 g, 0.613 mmol) and
tert-butyl (1-hydroxy-2,4-dimethylpentan-2-yl)carbamate (0.284 g, 1.226 mmol) were subjected
to ether synthesis as described in Example 16, Part H, to afford product,
tert-butyl(2,4-dimethyl-1-((6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (0.3 g, 28% yield) as pale yellow
solid. LC/MS (ESI)
m/
e 440.2 [(M+H)
+, calcd for C
25H
14N
3O
4, 440.2]; LC/MS retention time (method C):
tR = 2.67 min.

Part B: 8-((2-amino-2,4-dimethylpentyl)oxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0392] tert-Butyl (2,4-dimethyl-1-((6-methyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate was subjected to deprotection of
the Boc group as described in Example 2, Part E to afford 8-((2-amino-2,4-dimethylpentyl)oxy)-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (30 mg, 12% yield) as an off-white solid. Resolution of 8-((2-amino-2,4-dimethylpentyl)oxy)-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one by chiral HPLC (Co-solvent: 0.3% DEA in methanol, Column: Chiralpak AD H (250
x 21) mm 5u) resulted into two enantiomers.
Enantiomer-1: LC/MS (ESI)
m/
e 340.0 [(M+H)
+, calcd for C
20H
26N
3O
2,340.2]; LC/MS retention time (Method C):
tR = 1.88 min. HPLC retention time (method B):
tR = 9.29 min; HPLC retention time (method A):
tR = 8.19 min.
1H NMR (400 MHz, METHANOL-d
4) 9.43 (s, 1H), 8.73 (d,
J=6.0 Hz, 1H), 8.35 (d,
J=8.5 Hz, 1H), 8.19 (d,
J=6.0 Hz, 1H), 7.12 - 7.01 (m, 2H), 4.05 - 3.92 (m, 2H), 3.77 (s, 3H), 1.95 - 1.80
(m, 1H), 1.58 (qd,
J=14.2, 5.5 Hz, 2H), 1.30 (s, 3H), 1.04 (d,
J=6.5 Hz, 3H), 1.01 (d,
J=6.5 Hz, 3H); HPLC retention time,
tR = 5.44 min.
Enantiomer-2: LC/MS (ESI)
m/
e 340.0 [(M+H)
+, calcd for C
20H
26N
3O
2,340.2]; LC/MS retention time (Method C):
tR = 1.88 min. HPLC retention time (method B):
tR = 9.29 min; HPLC retention time (method A): t
R = 8.19 min.
1H NMR (400 MHz, METHANOL-d
4) 9.43 (s, 1H), 8.73 (d,
J=6.0 Hz, 1H), 8.35 (d,
J=8.5 Hz, 1H), 8.19 (d,
J=6.0 Hz, 1H), 7.12 - 7.01 (m, 2H), 4.05 - 3.92 (m, 2H), 3.77 (s, 3H), 1.95 - 1.80
(m, 1H), 1.58 (qd,
J=14.2, 5.5 Hz, 2H), 1.30 (s, 3H), 1.04 (d,
J=6.5 Hz, 3H), 1.01 (d,
J=6.5 Hz, 3H); HPLC retention time:
tR = 7.77 min.
Example 60
(S)-8-(2-amino-4-methylpentyloxy)-4-(difluoromethyl)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0393]

Part A: 8-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-4-carbaldehyde
[0394] To a solution of 8-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (100 mg, 0.387 mmol), prepared as described in Example 16, Part G, in AcOH (4
mL) was added selenium dioxide (51.5 mg, 0.464 mmol). The reaction mixture was allowed
to stir at 70 °C for 3h. Volatiles were removed under reduced pressure and the residue
so obtained was dissolved in dichloromethane (2 mL). The mixture was filtered through
diatomaceous earth (Celite
®) and the filtrate was concentrated under reduced pressure to afford the title product
(0.1 g, 0.202 mmol, 52% crude yield) as pale yellow solid. The material was carried
on without further purification. LC/MS, (ESI)
m/
z 273.0 [(M+H)
+, calcd for C
14H
10ClN
2O
2, 273.0]; LC/MS retention time (method H):
tR = 1.89 min.

Part B: 8-chloro-4-(difluoromethyl)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0395] To the solution of 8-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-4-carbaldehyde (200 mg, 0.733 mmol) in DCM (1 mL) was added bis-(2-methoxyethyl)aminosulfur
trifluoride (811 mg, 3.67 mmol). The tube was sealed and the reaction mixture was
allowed to stir at 50° C overnight. The reaction mixture was basified with saturated
aqueous NaHCO
3 (15 mL) and extracted with ethyl acetate (3x10 mL). The combined organic layers were
dried over Na
2SO
4 and concentrated under reduced pressure to afford 8-chloro-4-(difluoromethyl)-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (43 mg, 0.092 mmol, 13% crude yield) as a white solid. The material was carried
on without further purification. LC/MS, (ESI)
m/
z 295.0 [(M+H)
+, calcd for C
14H
10ClF
2N
2O, 295.0]; LC/MS retention time (Method H):
tR = 1.96 min.

Part C: (S)-tert-butyl (1-((4-(difluoromethyl)-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0396] Preparation as described in Example 16, Part H to afford the title compound (15 mg,
0.016 mmol, 19% yield). LC/MS, (ESI)
m/
z 476.3 [(M+H)
+, calcd for C
25H
32F
2N
3O
4 476.2]; LC/MS retention time (method E):
tR = 1.14 min.

Part D: (S)-8-((2-amino-4-methylpentyl)oxy)-4-(difluoromethyl)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0397] Preparation as described in Example 2, Part E to afford title product (1.5 mg, 3.95
µmol, 9% yield) as an off-white solid. LC/MS, (ESI)
m/
z 376.2 [(M+H)
+, calcd for C
20H
24F
2N
3O
2, 376.2]; LC/MS retention time (method C):
tR = 1.63 min. HPLC retention time (method A):
tR = 5.97 min; HPLC retention time (method B):
tR = 7.12 min.
1H NMR (400 MHz, METHANOL-
d4) δ ppm 8.81 (d,
J=5.52 Hz, 1H) 8.42 - 8.48 (m, 2H) 7.97 - 8.26 (m, 1H) 7.09 - 7.15 (m, 2H) 4.22 (dd,
J=9.54, 4.02 Hz, 1H) 4.04 (dd,
J=9.29, 7.03 Hz, 1H) 3.79 (s, 3H) 3.39 (dt,
J=3.33, 1.73 Hz, 1H) 1.81 - 1.92 (m, 1H) 1.43 - 1.57 (m, 2H) 1.02 (dd,
J=8.78, 6.53 Hz, 6H).
19F NMR (400 MHz, METHANOL-d
4) δ ppm 120.45.
Example 61
(S)-8-((2-amino-4-methylpentyl)oxy)-7-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0398]

Part A: (S)-tert-butyl (1-((7 or 9-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0399] To a solution of (
S)-
tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (50 mg, 0.114 mmol), prepared
as described in Example 16, Part H, in acetonitrile (2 mL) was added 1-chloropyrrolidine-2,5-dione
(15.19 mg, 0.114 mmol). The reaction mixture was allowed to stir at 55 °C for 16 h
overnight. The reaction mixture was basified with saturate aqueous sodium bicarbonate
(2 mL) and water (10 mL). The solution was extracted with methylene dichloride (3
x 10 mL). The combined organic layers were washed with brine (10 mL), dried with sodium
sulfate, filtered and concentrated under reduced pressure to afford a mixture of (
S)-
tert-butyl (1-((7-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate and (
S)-
tert-butyl (1-((9-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (60 mg, 0.037 mmol, 32%
combined crude yield) as a pale yellow solid. The material was carried on without
further purification. LC/MS (ESI)
m/
e 474.4, [(M+H)
+, calcd for C
25H
33ClN
3O
4, 474.2]; LC/MS retention time (method E):
tR = 1.24 min.

Part B: (S)-8-((2-amino-4-methylpentyl)oxy)-7-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0400] To a mixture of (
S)-
tert-butyl (1-((7-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate and (
S)-
tert-butyl (1-((9-chloro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (30 mg, 0.063 mmol) was
added HCl in 1,4-dioxane (241 µL, 0.964 mmol) at 0° C. The reaction mixture was allowed
to stir for 2 h, then was concentrated under reduced pressure. The residue was purified
by reverse phase HPLC (Symmetry C18 column (19 x 250 mm) 7.0 micron; mobile phase
A: 0.1 % TFA in water; mobile phase B: acetonitrile; flow rate: 14.0 mL). The HPLC
fractions were concentrated, basified with NaHCO
3 and extracted with DCM (2x). The combined organic layers were concentrated
in vacuo to afford the purified mixture of 7-Cl and 9-Cl final products as an off-white solid.
This was subjected to second purification (to resolve regioisomers) by normal phase
HPLC (chiralpak ODH, (4.6 X 250 mm) 5.0 micron; mobile phase A: n-hexane; mobile phase
B: ethanol); The HPLC fractions were concentrated
in vacuo to afford the 7-chloro-regioisomer: (
S)-8-((2-amino-4-methylpentyl)oxy)-7-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (3 mg, 7.2 umol, 11% yield) as a pale yellow solid. LC/MS, (ESI)
m/
z 373.8 [(M+H)
+, calcd for C
20H
25ClN
1O
2, 374.2]; LC/MS retention time (method C):
tR = 1.64 min. HPLC retention time (method A):
tR = 8.44 min;
1H NMR (400 MHz, DMSO-
d6) δ ppm 8.65 (d,
J=5.65 Hz, 1 H) 8.44 (d,
J=9.22 Hz, 1 H) 8.20 (d,
J=5.58 Hz, 1 H) 7.22 (d,
J=9.04 Hz, 1 H) 4.05 - 4.10 (m, 1 H) 3.98 (dd,
J=9.25, 6.43 Hz, 1 H) 3.73 (s, 3 H) 3.13 - 3.18 (m, 1 H) 2.99 (s, 3 H) 1.81 - 1.89
(m, 1 H) 1.28 - 1.42 (m, 2 H) 0.91 (dd,
J=13.80, 6.59 Hz, 2 H).
Example 62
(S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-56H)-one
[0401]

[0402] The mixture of 7-Cl and 9-Cl products prepared in Example 61, Part B was purified
(to resolve regioisomers) as shown above by normal phase HPLC (chiralpak ODH, (4.6
X 250 mm) 5.0 micron; mobile phase A: n-hexane; mobile phase B: esthanol); The HPLC
fractions were concentrated
in vacuo to afford the 9-chloro-regioisomer: (
S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (5 mg, 0.013 mmol, 21% yield) as an off white solid. LC/MS, (ESI)
m/
z 373.8 [(M+H)
+, calcd for C
20H
25ClN
3O
2, 374.2]; LC/MS retention time (method C):
tR = 1.61 min. HPLC retention time (method A):
tR = 8.37 min; HPLC retention time (method B):
tR = 9.14 min.
1H NMR (400 MHz, DMSO-
d6) δ ppm 8.63 (d,
J=5.65 Hz, 1 H) 8.60 (s, 1 H) 8.26 (d,
J=5.71 Hz, 1 H) 7.12 (s, 1 H) 4.11 - 4.16 (m, 1 H) 4.00 - 4.06 (m, 1 H) 3.70 (s, 3
H) 3.13-3.16 (m, 1H) 3.00 (s, 3 H) 1.82 - 1.90 (m, 1 H) 1.34 - 1.42 (m, 1 H) 1.23
- 1.32 (m, 1 H) 0.90-0.95 (m, 6 H).
Example 63
(S)-8-(2-amino-4-methylpentyloxy)-4,6,9-trimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0403]

Part A: (S)-tert-butyl (4-methyl-1-((4,6,9-trimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
[0404] Prepared as described in Example 3, Part A and Example 4, Part A to afford (
S)-
tert-butyl (4-methyl-1-((4,6,9-trimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate
(30 mg, 0.038 mmol, 40% yield) as a pale yellow solid. LC/MS, (ESI)
m/
z 453.9 [(M+H)
+, calcd for C
26H
36N
3O
4 454.3]; LC/MS retention time (method C):
tR = 2.16 min.

Part B: (S)-8-((2-amino-4-methylpentyl)oxy)-4,6,9-trimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0405] Prepared as described in Example 2, Part E to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-4,6,9-trimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (15 mg, 0.040 mmol, 62% yield) as an off-white solid. LC/MS, (ESI)
m/
z 353.9 [(M+H)
+, calcd for C
21H
28N
3O
2 354.2]; LC/MS retention time (method C):
tR = 1.64 min. HPLC retention time (method A):
tR = 8.21 min.
1H NMR (400 MHz, DMSO-
d6) δ ppm 8.59 (d,
J=5.77 Hz, 1H) 8.27 (s, 1H) 8.15 (d,
J=5.60 Hz,1H) 6.92 (s, 1H) 3.90 - 4.08 (m, 2H) 3.68 (s, 3H) 3.12 - 3.20 (m, 1H) 2.99
(s, 3H) 2.24(s, 3H) 1.85 (td,
J=13.68, 6.53 Hz, 3H) 1.22 - 1.43 (m, 3H) 0.86 - 0.95 (m, 6H).
Example 64
(S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carbonitrile
[0406]

Part A. (S)-tert-butyl 1-(9-cyano-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0407] A suspension of (
S)-
tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (2.4 g, 4.63 mmol), prepared
as described in Example 3, Part A, Pd
2(dba)
3 (0.212 g, 0.231 mmol), DPPF (0.257 g, 0.463 mmol) and zinc(II) cyanide (0.544 g,
4.63 mmol) in DMF (20 mL) and water (1 mL) was degassed with nitrogen and heated to
130 °C overnight. Ater cooling to room temperature, the volatiles were concentrated
under reduced pressure. The residue was reconstituted in ethyl acetate and filtered
through diatomaceous earth (Celite
®). The organic layer was washed with H
2O, followed by brine, dried over Na
2SO
4 and concentrated under reduced pressure. The crude product was purified by silica
gel column (petroleum ether and ethyl acetate) to afford (
S)-
tert-butyl 1-(9-cyano-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate (1.9 g, 4.09 mmol, 88% yield)
as a yellow solid. LC/MS (ESI)
m/
e 465.2 [(M+H)
+, calcd for C
26H
33N
4O
4, 465.2]; LC/MS retention time (method C):
tR = 2.74 min.

Part B. (S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carbonitrile
[0408] Prepared as described in Example 2, Part E to afford (
S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carbonitrile (1.6 g, 3.89 mmol, 95 % yield) as a light yellow
solid. LC/MS (ESI)
m/
e 365.2 [(M+H)
+, calcd for C
21H
25N
4O
2, 365.2]; LC/MS retention time (method C):
tR = 2.13 min. HPLC retention time (method A):
tR = 8.70 min; HPLC retention time (method B):
tR = 9.57 min.
1H NMR (400 MHz,
MeOD) δ ppm 9.07 (s, 1 H), 8.75 (s, 2 H), 7.28 (s, 1 H), 4.69 (m, 1 H), 4.55 (m, 1 H),
3.87 (m, 4 H), 3.27 (s, 3 H), 1.87 (m, 2 H), 1.74 (m, 1 H), 1.08 (m, 6 H).
Example 65
(S)-4,6-dimethyl-8-(4-methyl-2-(methylamino)pentyloxy)-5-oxo-5,6-dihydrobenzo[c] [2,7]naphthyridine-9-carbonitrile
[0409]

Part A. (S)-tert-butyl (1-((9-cyano-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)(methyl)carbamate
[0410] (S)-
tert-Butyl (1-((9-cyano-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (60 mg, 0.129 mmol), prepared
as described in Example 64, Part B, was taken in DMF (3 mL) and cooled to 0°C. The
reaction mixture was treated with NaH (10.33 mg, 0.258 mmol) followed by MeI (0.016
mL, 0.258 mmol). After stirring at 0°C for 10 min, the reaction mixture was warmed
to room temperature and stirred overnight. The mixture was then quenched with ice-cold
water and extracted with ethyl acetate (2x3 mL). The combined organic layers were
dried with sodium sulfate and concentrated under reduced pressure to afford (
S)-
tert-butyl (1-((9-cyano-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)(methyl)carbamate
(70 mg, 0.127 mmol, 99% crude yield) as an off-white solid. The material was carried
forward without further purification. LC/MS (ESI)
m/
e 479.2 [(M+H)
+, calcd for C
27H
35N
4O
4 479.3]; LC/MS retention time (method C):
tR = 2.16 min.

Part B. (S)-4,6-dimethyl-8-((4-methyl-2-(methylamino)pentyl)oxy)-5-oxo-5,6-dihydrobenzo[c] [2,7]naphthyridine-9-carbonitrile
[0411] Prepared as described in Example 2, Part E to afford (
S)-4,6-dimethyl-8-((4-methyl-2-(methylamino)pentyl)oxy)-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carbonitrile
(25 mg, 0.058 mmol, 46% yield) as an off-white solid. LC/MS (ESI)
m/
e 379.0, [(M+H)
+, calcd for C
22H
27N
4O
2 379.2]; LC/MS retention time (method C):
tR = 1.87 min. HPLC retention time (method A):
tR = 8.59 min; HPLC retention time (method B):
tR = 9.88 min.
1H-NMR (400 MHz, MeOD): δ ppm 1.03 (d,
J = 22.80 Hz, 6H), 1.56-1.62 (m, 1H), 1.67-1.72 (m, 1H), 1.84-1.87 (m, 1H), 2.67 (s,
3H), 3.10 (s, 3H), 3.28-3.30 (m, 1H), 3.81 (s, 3H), 4.35 (s, 1H), 4.49 (s, 1H), 7.18
(s, 1H), 8.20 (d,
J= 5.60 Hz, 1H), 8.82 (s, 1H).
Example 66
(S)-8-((2-amino-4-methylpentyl)oxy)-2,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0412]

Part A: Methyl 4-chloro-6-methylnicotinate
[0413] To a solution of methyl 4,6-dichloronicotinate (3.00 g, 14.56 mmol) and trimethylboroxine
(1.097 g, 8.74 mmol) in 1,4-dioxane (70 mL) and water (7 mL) was added cesium carbonate
(14.23 g, 43.7 mmol). The mixture was degassed with argon over a period of 5 minutes.
PdCl
2(dppf)-CH
2Cl
2 adduct (1.189 g, 1.456 mmol) was added and the reaction mixture was heated to 110
°C for 16 h. The reaction mixture was cooled to room temperature, diluted with water
(100 mL) and extracted with ethyl acetate (200 mL). The organic phase was washed with
brine (2x100 mL), dried over Na
2SO
4, and concentrated under reduced pressure. The residue obtained was purified by silica
gel chromatography using ethyl acetate-petroleum ether mixture to afford methyl 4-chloro-6-methylnicotinate
(700 mg, 2.87 mmol, 20% yield) as a yellow liquid. LC/MS (ESI)
m/
e 186.0 [(M+H)
+, calcd for C
8H
9ClNO
2 185.6]; LC/MS retention time (Method I)
tR = 1.79 min.

Part B: Methyl 4-(4-chloro-2-fluorophenyl)-6-methylnicotinate
[0414] To a solution of methyl 4-chloro-6-methylnicotinate (660 mg, 3.56 mmol) and (4-chloro-2-fluorophenyl)boronic
acid (620 mg, 3.56 mmol) in 1,4-dioxane (20 mL) was added cesium carbonate (3.48 g,
10.67 mmol). The reaction mixture was degassed with argon over a period of 5 min.
Pd(Ph
3P)
4 (205 mg, 0.178 mmol) was added to the reaction mixture and heated to 80 °C for 16h.
The mixture was cooled to room temperature, diluted with water, and extracted with
ethyl acetate (100 mL). The organic phase was washed with brine (2x50 mL), dried over
Na
2SO
4, and concentrated under reduced pressure. The residue obtained was purified by silica
gel chromatography to afford methyl 4-(4-chloro-2-fluorophenyl)-6-methylnicotinate
(500 mg, 1.53 mmol, 43% yield) as a yellow liquid. LC/MS (ESI)
m/
e 280.0 [(M+H)
+, calcd for C
14H
12ClFNO
2 279.6]; LC/MS retention time (method C):
tR = 1.87 min.

Part C: 4-(4-chloro-2-fluorophenyl)-6-methylnicotinic acid
[0415] To a solution of methyl 4-(4-chloro-2-fluorophenyl)-6-methylnicotinate (700 mg, 2.50
mmol) in MeOH (5 mL) was added NaOH (200 mg, 7.51 mmol) in water (5 mL). The reaction
mixture was stirred at room temperature for 2h. The solvent was evaporated under reduced
pressure and the residue obtained was adjusted to pH ~3 by adding 1.5N HCl. The meaction
mxture was extracted with dichloromethane. The organic phase was dried over Na
2SO
4, and concentrated under reduced pressure to afford 4-(4-chloro-2-fluorophenyl)-6-methylnicotinic
acid (500 mg, 1.730 mmol, 92 % crude yield) as white solid. The material was carried
forward without further purification. LC/MS (ESI)
m/
e 266.0 [(M+H)
+, calcd for C
13H
10ClFNO
2 266.03]; LC/MS (Method I)
tR = 1.51 min.

Part D: 4-(4-chloro-2-fluorophenyl)-N,6-dimethylnicotinamide
[0416] To a solution of 4-(4-chloro-2-fluorophenyl)-6-methylnicotinic acid (500 mg, 1.88
mmol) in dichloromethane (10 mL) at 0 °C was added oxalyl chloride (0.988 mL, 11.29
mmol) drop wise followed by DMF (0.2 mL). The reaction mixture was stirred at room
temperature for 4h. The reaction mixture was evaporated to dryness. The residue was
taken in up dichloromethane (50 mL) and cooled to 0 °C. Methylamine hydrochloride
(1.27 g, 18.82 mmol) was added to followed by triethylamine (2.62 mL, 18.82 mmol)
and the reaction mixture was stirred at room temperature for 2h. The reaction mixture
was diluted with water (50 mL) and extracted with dichloromethane (100 mL). The organic
layer was separated, dried over Na
2SO
4 and concentrated under reduced pressure to afford 4-(4-chloro-2-fluorophenyl)-
N,6-dimethylnicotinamide (520 mg, 1.43 mmol, 76% crude yield) as yellow solid. The
material was carried forward without further purification. LC/MS (ESI)
m/
e 279.0 [(M+H)
+, calcd for C
14H
13ClFN
2O 279.1]; LC/MS retention time ((Method I)
tR = 1.82 min.

Part E: 8-chloro-2,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0417] To a solution of 4-(4-chloro-2-fluorophenyl)-N,6-dimethylnicotinamide (520 mg, 1.86
mmol) in tetrahydrofuran (20 mL) at 0 °C was added NaH (224 mg, 5.60 mmol). The reaction
mixture was brought to room temperature gradually and stirred at room temperature
for 15h. The reaction mixture was diluted with water (50 mL) and extracted with ethyl
acetate (100 mL). The organic layer was separated, dried over Na
2SO
4 and concentrated under reduced pressure to afford 8-chloro-2,6 dimethylbenzo[
c][2,7]naphthyridin-5(6
H)-one (480 mg, 1.51 mmol, 81% yield) as a brick-red solid. LC/MS (ESI)
m/
e 259.0 [(M+H)
+, calcd for C
14H
12ClN
2O 259.05]; LC/MS retention time (method C):
tR = 1.91 min.
1H NMR (400 MHz, METHANOL-d
4) δ ppm 9.41 (s, 1 H), 8.48 (d,
J=8.59 Hz, 1 H), 8.23 (s, 1 H), 7.69 (d,
J=1.98 Hz, 1 H), 7.44 (dd,
J=8.64, 1.94 Hz, 1 H), 3.78 (s, 3 H), 2.75 (s, 3 H).

Part F: (S)-tert-butyl (1-((2,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0418] To the stirred solution of 8-chloro-2,6-dimethylbenzo[c][2,7]naphthyridin-5(
6H)-one (100 mg, 0.387 mmol) and
tert-butyl (1-hydroxy-2,4-dimethylpentan-2-yl)carbamate (168 mg, 0.773 mmol) in toluene
(5 mL) was added cesium carbonate (189 mg, 0.580 mmol) and 2-di-
t-butylphosphino-2',4',6'-tri-
i-propyl-1,1'-biphenyl (9.85 mg, 0.023 mmol). The reaction mixture was degassed with
argon for 5 minutes and palladium(II) acetate (26 mg, 0.116 mmol) was added. The reaction
mixture was heated to 100 °C for 18h. The reaction mixture was filtered through diatomaceous
earth (Celite
®) and the filtrate was concentrated under reduced pressure. The residue was purified
by silica gel chromatography using ethyl acetate-petroleum ether to afford (
S)-
tert-butyl (1-((2,6-dimethyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (100 mg, 0.171 mmol, 44%
yield) as a dark yellow semi-solid. LC/MS (ESI)
m/
e 440.6 [(M+H+)
+, calcd for C
25H
34N
3O
4 440.2]; LC/MS retention time (method D):
tR = 0.89 min.

Part G: (S)-tert-butyl (1-((9-bromo-2,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0419] To the stirred solution of
(S)-
tert-butyl (1-((2,6-dimethyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (40 mg, 0.069 mmol) in
acetonitrile (3 mL) at room temperature was added NBS (12 mg, 0.069 mmol). The reaction
mixture was heated to reflux for 2h. The reaction mixture was diluted with water (50
mL) and extracted with dichloromethane (100 mL). The organic layer was separated,
dried over Na
2SO
4 and concentrated under reduced pressure to afford (
S)-
tert-butyl (1-((9-bromo-2,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (30 mg, 0.027 mmol, 40%
crude yield) as a yellow oil. The material was carried forward without further purification.
LC/MS (ESI)
m/
e 518.2 [(M+H)
+, calcd for C
25H
33BrN
3O
4 518.2]; LC/MS retention time (method E):
tR = 1.25 min.

Part H: (S)-8-((2-amino-4-methylpentyl)oxy)-2,6-dimethylbenzo[c] [2,7]naphthyridin-5(6H)-one
[0420] To a solution of (
S)-
tert-butyl (1-((9-bromo-2,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (30 mg, 0.058 mmol) in
MeOH (3 mL) at 0 °C was added 4M HCl in 1,4-dioxane (0.362 mL, 1.447 mmol). The reaction
mixture was stirred at 0 °C for 2h. The reaction mixture was concentrated under reduced
pressure to afford crude product which was purified by preparative HPLC to afford
(
S)-8-((2-amino-4-methylpentyl)oxy)-2,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (6 mg, 0.014 mmol, 24% yield) as an off-white solid. LC/MS (ESI)
m/
e 418.0 [(M+H)
+, calcd for C
20H
25BrN
3O
2 418.1]; LC/MS retention time (method H):
tR = 1.70 min; HPLC retention time (method A):
tR = 6.33 min; HPLC retention time (method B):
tR = 7.19 min.
1H NMR (400 MHz, METHANOL-d
4) δ ppm 9.31 (s, 1 H), 9.28 - 9.33 (m, 1 H), 8.58 (s, 1 H), 8.08 (s, 1 H), 7.09 (s,
1 H), 4.42 (dd,
J=9.79, 3.26 Hz, 1 H), 4.25 (dd,
J=9.91, 6.15 Hz, 1 H), 3.78 (s, 3 H), 3.63 (br. s., 1 H), 2.73 (s, 3 H), 2.00 (br.
s., 4 H), 1.85 - 1.92 (m, 1 H), 1.71 - 1.80 (m, 1 H), 1.57 - 1.66 (m, 1 H), 1.06 (dd,
J=6.40, 4.64 Hz, 6 H).
Example 67
(S)-8-((2-amino-4-methylpentyl)oxy)-2,6 dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0421]

Part A: Methyl 4-chloro-6-methylnicotinate
[0422] To a solution of methyl 4,6-dichloronicotinate (3.00 g, 14.56 mmol) and trimethylboroxine
(1.097 g, 8.74 mmol) in 1,4-dioxane (70 mL) and water (7 mL), was added cesium carbonate
(14.23 g, 43.7 mmol). The mixture was degassed with argon over a period of 5 min.
PdCl
2(dppf)-CH
2Cl
2 adduct (1.189 g, 1.456 mmol) was added to the reaction mixture and heated to 110
°C for 16h. The reaction mixture was cooled to room temperature, diluted with water
(100 mL) and extracted with ethyl acetate (200 mL). The organic phase was washed with
brine (2 x 100 mL), dried over Na
2SO
4, and concentrated under reduced pressure. The residue obtained was purified by silica
gel chromatography using ethyl acetate-petroleum ether mixture to afford methyl 4-chloro-6-methylnicotinate
(700 mg, 2.87 mmol, 20% yield) as a yellow liquid. LC/MS (ESI)
m/
e 186.0 [(M+H)
+, calcd for C
8H
9ClNO
2 186.0]; LC/MS retention time (Method I):
tR = 1.79 min.

Part B: Methyl 4-(4-chloro-2-fluorophenyl)-6-methylnicotinate
[0423] To a solution of methyl 4-chloro-6-methylnicotinate (660 mg, 3.56 mmol) and (4-chloro-2-fluorophenyl)boronic
acid (620 mg, 3.56 mmol) in 1,4-dioxane (20 mL) was added cesium carbonate (3.48 g,
10.67 mmol). The reaction mixture was degassed with argon over a period of 5 min.
Pd(Ph
3P)
4 (205 mg, 0.178 mmol) was added to the reaction mixture and heated to 80 °C for 16h.
The mixture was cooled to room temperature, diluted with water, and extracted with
ethyl acetate (100 mL). The organic phase was washed with brine (2 x 50 mL), dried
over Na
2SO
4, and concentrated under reduced pressure. The residue obtained was purified by silica
gel chromatography to afford Methyl 4-(4-chloro-2-fluorophenyl)-6-methylnicotinate
(500 mg, 1.53 mmol, 43% yield) as a yellow liquid. LC/MS (ESI)
m/
e 280.0 [(M+H)
+, calcd for C
14H
12ClFNO
2 280.0]; LC/MS retention time (Method C):
tR = 1.87 min.

Part C: 4-(4-chloro-2-fluorophenyl)-6-methylnicotinic acid
[0424] To a solution of Methyl 4-(4-chloro-2-fluorophenyl)-6-methylnicotinate (700 mg, 2.50
mmol) in MeOH (5 mL) was added NaOH (200 mg, 7.51 mmol) in water (5 mL). The reaction
mixture was stirred at room temperature for 2h. Then it was evaporated under reduced
pressure and the residue obtained was adjusted to pH ~3 by adding 1.5N HCl solution.
The product was extracted with dichloromethane. The organic phase was dried over Na
2SO
4, and concentrated under reduced pressure to afford 4-(4-chloro-2-fluorophenyl)-6-methylnicotinic
acid (500 mg, 1.730 mmol, 69% crude yield) as white solid. The material was carried
forward without further purification. LC/MS (ESI)
m/
e 266.0 [(M+H)
+, calcd for C
13H
10ClFNO
2 266.0]; LC/MS retention time (Method I):
tR = 1.51 min.

Part D: 4-(4-chloro-2-fluorophenyl)-N,6-dimethylnicotinamide
[0425] To a solution of 4-(4-chloro-2-fluorophenyl)-6-methylnicotinic acid (500 mg, 1.88
mmol) in dichloromethane (10 mL) at 0 °C was added oxalyl chloride (0.988 mL, 11.29
mmol) drop wise followed by DMF (0.2 mL). The reaction mixture was stirred at room
temperature for 4h. The reaction mixture was evaporated to dryness. The residue was
taken in dichloromethane (50 mL) and cooled to 0 °C. Methylamine hydrochloride (1.27
g, 18.82 mmol) and triethylamine (2.62 mL, 18.82 mmol) were added. The reaction mixture
was stirred at room temperature for 2h. The reaction mixture was diluted with water
(50 mL) and extracted with dichloromethane (100 mL). The organic layer was separated,
dried over Na
2SO
4 and concentrated under reduced pressure to afford 4-(4-chloro-2-fluorophenyl)-N,6-dimethylnicotinamide
(520 mg, 1.43 mmol, 76% crude yield) as yellow solid. The material was carried forward
without further purification. LC/MS (ESI)
m/
e 279.0 [(M+H)
+, calcd for C
14H
13ClFN
2O 279.1]; LC/MS retention time ( Method I):
tR = 1.82 min.

Part E: 8-chloro-2,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0426] To a solution of 4-(4-chloro-2-fluorophenyl)-N,6-dimethylnicotinamide (520 mg, 1.86
mmol) in tetrahydrofuran (20 mL) at 0 °C was added NaH (224 mg, 5.60 mmol). The reaction
mixture was brought to room temperature gradually and stirred at room temperature
for 15h. The reaction mixture was diluted with water (50 mL) and extracted with ethyl
acetate (100 mL). The organic layer was separated, dried over Na
2SO
4 and concentrated under reduced pressure to afford product, 8-chloro-2,6 dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (480 mg, 1.51 mmol, 81% crude yield) as a red solid. The material was carried
forward without further purification. LC/MS (ESI)
m/
e 259.0 [(M+H)
+, calcd for C
14H
12ClN
2O 259.0]; LC/MS retention time (Method C):
tR = 1.74 min.
1H NMR (300 MHz, METHANOL-
d4) δ ppm 9.41 (s, 1 H), 8.48 (d,
J=8.59 Hz, 1 H), 8.23 (s, 1 H), 7.69 (d,
J=1.98 Hz, 1 H), 7.44 (dd,
J=8.64, 1.94 Hz, 1 H), 3.78 (s, 3 H), 2.75 (s, 3 H).

Part F: (S)-tert-butyl (1-((2,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0427] To the stirred solution of 8-chloro-2,6-dimethylbenzo[c][2,7]naphthyridin-5(
6H)-one (100 mg, 0.387 mmol) and
tert-butyl (1-hydroxy-2,4-dimethylpentan-2-yl)carbamate (168 mg, 0.773 mmol) in toluene
(5 mL) was added cesium carbonate (189 mg, 0.580 mmol) and 2-di-
t-butylphosphino-2',4',6'-tri-
i-propyl-1,1'-biphenyl (9.85 mg, 0.023 mmol). The reaction mixture was degassed with
argon for 5 min and palladium(II) acetate (26 mg, 0.116 mmol) was added to it. The
reaction mixture was heated to 100 °C for 18h. The reaction mixture was filtered through
diatomaceous earth (Celite
®) and the filtrate was evaporated. The residue obtained was purified by silica gel
chromatography using ethyl acetate-petroleum ether to afford product, (S)-
tert-butyl (1-((2,6-dimethyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (100 mg, 0.171 mmol, 44%
yield) as dark yellow semi-solid. LC/MS (ESI)
m/
e 440.7 [(M+H)
+, calcd for C
25H
34N
3O
4 440.2]; LC/MS retention time (method D):
tR = 0.89 min.

Part G. (S)-8-((2-amino-4-methylpentyl)oxy)-2,6 dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0428] (S)-
tert-Butyl (1-((2,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.05 g, 0.114 mmol) was
subjected to deprotection of the Boc group as described in Example 2, Part E, to give
(S)-8-((2-amino-4-methylpentyl)oxy)-2,6 dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (13 mg, 0.037 mmol, 33%) as colorless semi-solid. LC/MS (ESI)
m/
e 340.2 [(M+H)
+, calcd for C
20H
26N
3O
2 340.2]; LC/MS retention time (Method I):
tR = 1.62 min. HPLC retention time (method A):
tR = 8.17 min; HPLC retention time (method B):
tR = 7.50 min.
1H NMR (400 MHz, METHANOL-
d4) ppm 9.33 (s, 1H), 8.38 (d,
J=8.78 Hz, 1H), 8.34 - 8.41 (m, 1H), 8.10 (s, 1H), 8.06 - 8.12 (m, 1H), 7.04 - 7.13
(m, 2H), 4.17 (dd,
J=9.29, 4.02 Hz, 1H), 3.99 (dd,
J=9.29, 7.28 Hz, 1H), 3.77 (s, 3H), 3.66 (d,
J=2.76 Hz, 1H), 2.72 (s, 3H), 1.80 - 1.92 (m, 1H), 1.39 - 1.54 (m, 2H), 1.01 (dd,
J=9.29, 6.53 Hz, 7H).
Example 68
(S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-2,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0429]

Part A. (S)-tert-butyl (1-((9-chloro-2,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0430] (
S)-
tert-butyl (1-((2,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.05 g, 0.114 mmol), prepared
as described in Example 67, Part F, was subjected to chlorination using NCS (0.018
g, 0.137 mmol), using the procedure described in Example 20, Part A, to give (
S)-
tert-butyl (1-((9-chloro-2,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (50 mg, 0.052 mmol, 45%
yield) as colorless oil. LC/MS (ESI)
m/
e 474.7 [(M+H)
+, calcd for C
25H
32ClN
3O
4 474.2]; LC/MS retention time (method H):
tR = 0.94 min.

Part B. (S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-2,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0431] (S)-
tert-Butyl (1-((9-chloro-2,6-dimethyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.04 g, 0.041 mmol) was
subjected to deprotection of the Boc group using the procedure described in Example
2, Part E, to afford (
S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-2,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.006 g, 0.015 mmol, 37% yield) as an off-white solid. LC/MS (ESI)
m/
e 373.8 [(M+H)
+, calcd for C
20H
25ClN
3O
2 374.2]; LC/MS retention time (Method C):
tR = 1.55 min; HPLC retention time (Method A):
tR = 10.18 min; HPLC retention time (Method B):
tR = 15.48 min.
1H NMR (400 MHz, METHANOL-
d4) ppm 9.37 (s, 1H), 8.46 - 8.53 (m, 1H), 8.14 (s, 1H), 7.19 (s,1H), 4.23 - 4.31 (m,
1H), 4.03 - 4.11 (m, 1H), 3.78 - 3.88 (m, 3H) 2.73 (s, 1H), 2.70 - 2.77 (m, 3H), 1.81
-1.90 (m, 1H), 1.44 - 1.58 (m, 2H), 0.96 - 1.06 (m, 6H).
Example 69
(S)-8-(2-amino-3-methoxypropoxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0432]

Part A: (R)-2-amino-3-methoxypropan-1-ol
Part B: (S)-benzyl (1-methoxy-3-((6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)propan-2-yl)carbamate
[0434] Preparation as described in Example 16, Part H to afford the title product (0.12
g, 0.145 mmol, 24% yield) yellow gum. LC/MS, (ESI)
m/
z 448.6 [(M+H)
+, calcd for C
25H
26N
3O
5, 448.5]; LC/MS retention time (method D):
tR = 0.74 min.

Part C: (S)-8-(2-amino-3-methoxypropoxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0435] Prepared as described in Example 2, Part E to afford the title product (14 mg, 0.042
mmol, 70% yield) as a brown gum. LC/MS, (ESI)
m/
z 314.2 [(M+H)
+, calcd for C
17H
20N
3O
3, 314.1]; LC/MS retention time (method C):
tR = 1.38 min. HPLC retention time (method A):
tR = 5.29 min; HPLC retention time (method B):
tR = 5.31 min.
1H NMR (400 MHz, METHANOL-
d4) δ ppm 9.47 (s, 1 H) 8.77 (d,
J=5.77 Hz, 1 H) 8.42 (d,
J=8.78 Hz, 1 H) 8.25 (d,
J=5.77 Hz, 1 H) 7.04 - 7.17 (m, 2 H) 4.26 (dd,
J=9.29, 4.77 Hz, 1 H) 4.10 - 4.19 (m, 1 H) 3.81 (s, 3 H) 3.52 - 3.65 (m, 2 H) 3.44
(s, 3 H) 3.38 (dt,
J=3.33, 1.73 Hz, 1 H).
Example 70
(S)-8-(2-amino-4-methylpentyloxy)-9-fluoro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0436]

Part A. Methyl 4-(4-chloro-2,5-difluorophenyl)-2-methylnicotinate
[0437] Prepared as described in Example 16, Part D by carrying out a Suzuki coupling between
methyl 4-chloro-2-methylnicotinate (prepared as described in Example 14, Part A) and
2-(4-chloro-2,5-difluorophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (prepared
as described in Example 16, Part A-Part C) to afford methyl 4-(4-chloro-2,5-difluorophenyl)-2-methylnicotinate
(3 g, 4.13 mmol, 24% yield) as a brown oil.
1H NMR (400 MHz,
CDCl3) δ ppm 8.60 (d,
J= 5.2 Hz, 1 H), 7.36 (m, 1 H), 7.20 (m, 2 H), 3.74 (s, 3 H), 2.49 (s, 3 H).

Part B. 4-(4-chloro-2,5-difluorophenyl)-2-methylnicotinic acid
[0438] Prepared as described in Example 16, Part E by carrying out hydrolysis of Methyl
4-(4-chloro-2,5-difluorophenyl)-2-methylnicotinate to afford 4-(4-chloro-2,5-difluorophenyl)-2-methylnicotinic
acid (1.7 g, 4.02 mmol, 97 % yield) as a white solid.
1H NMR (400 MHz,
DMSO-d6) δ ppm 13.38 (br. s., 1H), 8.58 (d,
J = 5.2 Hz, 1H), 7.74 (m, 1H), 7.53 (m, 1H), 7.41 (d,
J= 4.8 Hz, 1H), 2.43 (s, 3H).

Part C. 4-(4-chloro-2,5-difluorophenyl)-N,2-dimethylnicotinamide
[0439] To the stirred solution of 4-(4-chloro-2,5-difluorophenyl)-2-methylnicotinic acid
(1.7 g, 4.02 mmol) in DMF (0.5 mL) was added DIEA (2.81 mL, 16.06 mmol), HOBT (1.230
g, 8.03 mmol), EDC (1.155 g, 6.02 mmol) at 0 °C followed by addition of methylamine
hydrochloride (0.488 g, 7.23 mmol). After stirring for 10 min, the ice bath was removed
and the reaction mixture was allowed to stir overnight. The reaction mixture was concnetrated
under reduced pressure. The residue was diluted with ethyl acetate (10 mL) and washed
with water (10 mL) followed by brine (10 mL). The organic layer was separated and
dried over sodium sulphate, filtered, and concentrated under reduced pressure to afford
4-(4-chloro-2,5-difluorophenyl)-
N,2-dimethylnicotinamide (1 g, 2.123 mmol, 53% crude yield) as a brown solid which
was taken to the next step without purification. LC/MS (ESI)
m/
e 297.3 [(M+H)
+, calcd for C
14H
12ClF
2N
2O 297.1]; LC/MS retention time (method B):
tR = 0.76 min.

Part D. 8-chloro-9-fluoro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0440] Prepared as described in Example 16, Part G from 4-(4-chloro-2,5-difluorophenyl)-2-methylnicotinic
acid to afford 8-chloro-9-fluoro-4,6 dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (530 mg, 1.532 mmol, 72% yield) as a white solid. LC/MS (ESI)
m/
e 277.2 [(M+H)
+, calcd for C
14H
11ClFN
2O 277.04]; LC/MS retention time (method C):
tR = 1.83 min.

Part E. (S)-tert-butyl 1-(9-fluoro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0441] Prepared as described in Example 16, Part H from 8-chloro-9-fluoro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one to afford
(S)-tert-butyl1
-(9-fluoro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate (350 mg, 0.367 mmol, 24 %)
as an oil. LC/MS (ESI)
m/
e 458.6 [(M+H)
+, calcd for C
25H
33FN
3O
4 458.23]; LC/MS retention time (method B):
tR = 1.24 min.

Part F. (S)-8-(2-amino-4-methylpentyloxy)-9-fluoro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0442] Prepared as described in Example 16, Part I from
(S)-tert-butyl1-(9-fluoro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate to afford
(S)-8-(2-amino-4-methylpentyloxy)-9-fluoro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (57.6 mg, 0.095 mmol, 91 %) as an yellow oil. LC/MS (ESI)
m/
e 358.2 [(M+H)
+, calcd for C
20H
25FN
3O
2 358.2]; LC/MS retention time (method C):
tR = 1.53 min; HPLC retention time (method B):
tR = 8.16 min.
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.58 (d,
J=5.8 Hz, 1H), 8.23 (d,
J=12.0 Hz, 1H), 8.09 (d, J=5.0 Hz, 1H), 7.19 (d,
J=6.8 Hz, 1H), 4.26 (dd,
J=9.5, 4.0 Hz, 1H), 4.08 (t,
J=8.2 Hz, 1H), 3.79 (s, 3H), 3.41 - 3.38 (m, 1H), 3.10 (s, 3H), 1.94 - 1.82 (m, 1H),
1.58 - 1.39 (m, 2H), 1.04 (d,
J=6.5 Hz, 3H), 1.01 (d,
J=6.5 Hz, 3H).
Example 71
(S)-8-(2-amino-4-methylpentyloxy)-9-(hydroxymethyl)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0443]

Part A. (S)-tert-butyl1-(4,6-dimethyl-5-oxo-9-vinyl-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0444] Prepared as described in Example 64, Part A and Example 46, Part B from (
S)-
tert-butyl 1-(9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate to afford the title product
(1.2 g, 1.985 mmol, 64% yield). LC/MS (ESI)
m/
e 466.2 [(M+H)
+, calcd for C
27H
16N
3O
4 466.3]; LC/MS retention time (method B):
tR = 1.79 min.

Part B. (S)-tert-butyl 1-(9-formyl-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0445] Prepared as described in Example 55, Part B from
(S)-tert-butyl 1
-(4,6-dimethyl-5-oxo-9-vinyl-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate to afford the title product
(1.2 g, 0.980 mmol, 49% yield) as a yellow gum. LC/MS (ESI)
m/
e 468.2 [(M+H)
+, calcd for C
26H
14N
3O
5 468.2]; LC/MS retention time (method B):
tR = 1.66 min.

Part C. (S)-tert-butyl 1-(9-(hydroxymethyl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0446] Prepared as described in Example 31, Part E to afford the title product (0.100 g,
0.160 mmol, 87 % yield) as a brown gum. LC/MS (ESI)
m/
e 470.2 [(M+H)
+, calcd for C
26H
36N
3O
5 470.2]; LC/MS retention time (method B):
tR = 1.48 min.

Part D. (S)-8-(2-amino-4-methylpentyloxy)-9-(hydroxymethyl)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0447] Prepared as described in Example 2, Part E to afford the title product (28 mg, 0.073
mmol, 34% yield) as an off-white solid. LC/MS (ESI)
m/
e 370.2 [(M+H)
+, calcd for C
21H
28N
3O
3 370.2]; LC/MS retention time (method B):
tR = 1.03 min. HPLC retention time (method A):
tR = 7.46 min; HPLC retention time (method B):
tR = 8.13 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.55 (d,
J=5.8 Hz, 1H), 8.37 (s, 1H), 8.12 (d,
J=5.8 Hz, 1H), 7.01 (s, 1H), 4.80 (s, 2H), 4.28 (dd,
J=9.5, 3.5 Hz, 1H), 4.08 (dd,
J=9.5, 7.0 Hz, 1H), 3.78 (s, 3H), 3.48 - 3.40 (m, 1H), 3.08 (s, 3H), 1.92 - 1.80 (m,
1H), 1.64 - 1.41 (m, 2H), 1.05 (d,
J=6.5 Hz, 3H), 1.03 (d,
J=6.8 Hz, 3H).
Example 72
(S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(oxazol-5-yl)benzo[c][2,7]naphthyridin-5(6H)-one
[0448]

Part A. (S)-tert-butyl 1-(4,6-dimethyl-9-(oxazol-5-yl)-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0449] Prepared as described in an Example 71, Part D and Example 48, Part B from (
S)-
tert-butyl 1-(9-formyl-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate to afford the title product
(150 mg, 0.068 mmol, 56% yield) as a yellow gum. LC/MS (ESI)
m/
e 507.2 [(M+H)
+, calcd for C
28H
35N
4O
5 507.2] LC/MS retention time (method B):
tR = 1.64 min.

Part B. (S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(oxazol-5-yl)benzo[c][2,7]naphthyridin-5(6H)-one
[0450] Prepared as described in Example 2, Part E from (
S)-
tert-butyl 1-(9-formyl-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate to afford the title product
(20 mg, 0.045 mmol, 67% yield) as a yellow solid. LC/MS (ESI)
m/
e 407.2 [(M+H)
+, calcd for C
23H
27N
4O
3 407.2] LC/MS retention time (method B):
tR = 1.64 min. HPLC retention time (method A):
tR = 7.46 min; HPLC retention time (method A):
tR = 8.89 min HPLC retention time (method B):
tR = 8.80 min
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.66 (s, 1H), 8.57 (d,
J=5.8 Hz, 1H), 8.34 (s, 1H), 8.15 (d,
J=5.8 Hz, 1H), 7.60 (s, 1H), 7.08 (s, 1H), 4.38 - 4.26 (m, 1H), 4.24 - 4.17 (m, 1H),
3.76 (s, 3H), 3.48 (dd,
J=3.3, 1.8 Hz, 1H), 3.05 (s, 3H), 1.93 - 1.82 (m, 1H), 1.65 - 1.44 (m, 2H), 1.04 (d,
J=2.5 Hz, 3H), 1.02 (d,
J=2.5 Hz, 3H).
Example 73
8-(2-amino-5,5,5-trifluoropentyloxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carbonitrile
[0451]

8-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0452]

Part A. tert-butyl 1-(4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-5,5,5-trifluoropentan-2-ylcarbamate
[0453] Prepared as described in Example 16, Part H to afford
tert-butyl 1-(4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-5,5,5-trifluoropentan-2-ylcarbamate (300 mg, 0.416 mmol,
54 % yield) as a white solid.
1H LC/MS (ESI)
m/
e 480.2 [(M+H)
+, calcd for C
24H
29F
3N
3O
4 480.2] LC/MS retention time (method H):
tR = 2.22 min.

Part B. tert-butyl 1-(9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-5,5,5-trifluoropentan-2-ylcarbamate
[0454] Prepared as described in Example 3, Part A to afford the title product (50 mg, 0.06
mmol, 58 % yield) as a pale yellow solid.
1H LC/MS (ESI)
m/
e 559.0 [(M+2H)
+, calcd for C
24H
29BrF
3N
3O
4 559.1] LC/MS retention time (method C):
tR = 2.24 min.

Part C. tert-butyl 1-(9-cyano-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-5,5,5-trifluoropentan-2-ylcarbamate
[0455] Prepared as described in Example 64, Part B to afford the title product (40 mg, 0.079
mmol, 11 % yield) as a pale yellow solid. LC/MS (ESI)
m/
e 505.4 [(M+H)
+, calcd for C
25H
28F
3N
4O
4 505.2] LC/MS retention time (method E):
tR = 1.1 1 min.

Part D. 8-(2-amino-5,5,5-trifluoropentyloxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carbonitrile
[0456] Prepared as described in Example 2, Part E to afford the title product (50 mg, 0.036
mmol, 45 % yield) as an off white solid. LC/MS (ESI)
m/
e 405.4 [(M+H)
+, calcd for C
20H
20F
3N
4O
2 405.1]; LC/MS retention time (method E):
tR = 0.71 min. HPLC retention time (method A):
tR = 8.35 min; HPLC retention time (method B):
tR = 9.38 min.
1H NMR (400MHz, DMSO-d
6) δ ppm 8.98 (s, 1H), 8.67 (d,
J=5.6 Hz, 1H), 8.30 (d,
J=5.6 Hz, 1H), 7.12 (s, 1H), 4.19 (d,
J=6.0 Hz, 2H), 3.71 (s, 3H), 3.16 - 3.14 (m, 1H), 3.00 (s, 3H), 2.45 - 2.30 (m, 2H),
1.89 - 1.80 (m, 1H), 1.58 - 1.55 (m, 1H).
Example 74
(S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(trifluoromethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0457]

Part A. (S)-tert-butyl 1-(4,6-dimethyl-5-oxo-9-(1H-pyrazol-1-yl)-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0458] To the solution of
(S)-tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (50 mg, 0.096 mmol) and
1
H-pyrazole (7.88 mg, 0.116 mmol) in 1,4-dioxane (2 mL) and DMF (0.5 mL), was added copper(I)
iodide (18.37 mg, 0.096 mmol),
N1
,N2-dimethylethane-1,2-diamine (17.00 mg, 0.193 mmol) and potassium phosphate (61.4
mg, 0.289 mmol). The reaction mixture was degassed with nitrogen for 5 min and heated
to 170 °C for 1 h in a microwave. The reaction mixture was cooled to room temperature,
filtered through diatomaceous earth (elites
®) and the filtrate concentrated under reduced pressure. The residue was purified by
preparative TLC (eluent 2% MeOH :DCM) to afford
(S)-tert-butyl 1-(4,6-dimethyl-5-oxo-9-(1H-pyrazol-1-yl)-5,6-dihydrobenzo[c] [2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
(40 mg, 0.028 mmol, 29% yield) as a brown solid. LC/MS (ESI) m/e 406.5 [(M+H)
+, calcd for C
23H
28N
5O
2 406.2] LC/MS retention time (method E):
tR = 0.71 min.

Part B. (S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(trifluoromethyl)benzo[c] [2,7]naphthyridin-5(6H)-one
[0459] Prepared as described in Example 2, Part E from
(S)-tert-butyl 1
-(4,6-dimethyl-5-oxo-9-(1
H-pyrazol-1-yl)-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
to afford
(S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(trifluoromethyl)benzo[
c][2,7]naphthyridin-5
(6H)-one (2 mg, 0.005 mmol, 24% yield) as a green yellow semisolid. LC/MS (ESI) m/e 406.2
[(M+H)
+, calcd for C
23H
28N
5O
2 406.2]; HPLC retention time (method A):
tR = 8.37 min HPLC retention time (method B):
tR = 9.54 min;
1H NMR of racemic compound (400MHz, DMSO-d
6) δ ppm 8.98 (s, 1H), 8.67 (d,
J=5.6 Hz, 1H), 8.30 (d,
J=5.6 Hz, 1H), 7.12 (s, 1H), 4.19 (d,
J=6.0 Hz, 2H), 3.71 (s, 3H), 3.16 - 3.14 (m, 1H), 3.00 (s, 3H), 2.45 - 2.30 (m, 2H),
1.89 - 1.80 (m, 1H), 1.58 - 1.55 (m, 1H).
Example 75
(S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(trifluoromethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0460]

Part A. (S)-2-(1-(4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione
[0461] (S)-tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (300 mg, 0.683 mmol) was
taken up in AcOH (15 mL) and treated with periodic acid (156 mg, 0.683 mmol) and H
2SO
4 (0.018 mL, 0.341 mmol). The reaction mixture was heated to 80 °C for 20 min after
which time iodine (104 mg, 0.410 mmol) was added and heating was continued for an
additional 3 h. After cooling, the volatiles were evaporated. The residue was taken
up in ethyl acetate (25 mL) and organic layer was washed with saturated aqueous NaHCO
3 (10 mL), then brine (10 mL), dried with Na
2SO
4, filtered and concentrated under reduced pressure to afford
(S)-2-(1-(4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (300 mg, 0.61
mmol, 90% crude yield) as a brown solid. This was taken to the next step without further
purification. LC/MS (ESI) m/e 466.1 [(M+H)
+, calcd for C
20H
25IN
3O
2 466.1]; LC/MS retention time (method F):
tR = 0.58 min.

Part B. (S)-2-(1-(9-iodo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione
[0462] To a solution of
(S)-8-((2-amino-4-methylpentyl)oxy)-9-iodo-4,6-dimethylbenzo[
c][2,7]naphthyridin-5
(6H)-one (130 mg, 0.140 mmol) in 1,4-dioxane (3 mL) was added
N-ethyl-
N-isopropylpropan-2-amine (54.2 mg, 0.419 mmol) and isobenzofuran-1,3-dione (24.83
mg, 0.168 mmol). The reaction mixture was refluxed for 16 h. After cooling, the reaction
mixture was diluted with EtOAc (10 mL). The organics were washed with water, saturated
aqueous NaHCO
3. The combined aqueous layers were extracted with ethyl acetate (3 x 10 mL). The combined
organic layers were dried over sodium sulfate and concentrated under reduced pressure.
The residue was purified by preparative TLC plate using 2 % Methanol: DCM as a eluent
system to afford
(S)-2-(1-((9-iodo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (85 mg, 0.084
mmol, 60% yield) as a pale yellow solid. LC/MS (ESI) m/e 596.5 [(M+H)
+, calcd for C
28H
27IN
3O
4 596.1] LC/MS retention time (method E):
tR = 1.3 min.

Part C. (S)-2-(1-(4,6-dimethyl-5-oxo-9-(trifluoromethyl)-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione
[0463] Dried potassium fluoride (19.51 mg, 0.336 mmol) and copper(I) iodide (64.0 mg, 0.336
mmol) were mixed and heated to 200 °C under gentle shaking at reduced pressure (1
Torr) until a light yellow-greenish color appeared. After cooling, anhydrous
N-methyl-2-pyrrolidinone (1 mL) was added, followed by
(S)-2-(1-((9-iodo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (100 mg, 0.168
mmol) and trimethyl(trifluoromethyl)silane (0.075 mL, 0.504 mmol). The brown solution
thus obtained was heated at 90 °C for 16 h. After cooling, aqueous ammonia (10 mL)
was added to the reaction mixture. The reaction mixture was and extracted with ethyl
acetate (3x10 mL). The combined organic layers were wsahed with brine (1x10 mL), dried
over sodium sulfate and concentrated under reduced pressure. The residue was purified
by preparative TLC ( 50 % ethyl acetate: petroleum ether as eluent system) to afford
(S)-2-(1-(4,6-dimethyl-5-oxo-9-(trifluoromethyl)-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (80 mg, 0.033
mmol, 20% yield, 22% purity) as a pale yellow solid. LC/MS (ESI) m/e 538.6 [(M+H)
+, calcd for C
29H
27F
3N
3O
4 538.2] LC/MS retention time (method E):
tR = 1.27 min.

Part D. (S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(trifluoromethyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0464] To a solution of
(S)-2-(1-((4,6-dimethyl-5-oxo-9-(trifluoromethyl)-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (50 mg, 0.019
mmol) in EtOH (4 mL) was added hydrazine hydrate (6.52 mg, 0.130 mmol). The reaction
mixture was allowed to stir at 45 °C for 2 h. After cooling, the reaction mixture
was concentrated under reduced pressure. The residue was purified by reverse phase
HPLC (Symmetry C-18 column (19.0 x 250 mm) 7.0 micron; mobile phase A:Ammonium acetate
in water; mobile phase B: acetontirile; flow rate: 16.0 mL) to afford the
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-9 (trifluoromethyl)benzo[
c][2,7]naphthyridin-5
(6H)-one (5 mg, 0.012 mmol, 64% yield) as an off-white solid. LC/MS (ESI) m/e 408.2 [(M+H)
+, calcd for C
21H
25F
3N
3O
2 408.2] LC/MS retention time (method B):
tR = 1.25 min. HPLC retention time (method A):
tR = 10.10 min HPLC retention time (method B):
tR = 10.69 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.66 (s, 1H), 8.63 (d,
J=5.6 Hz, 1H), 8.22 (d,
J=5.6 Hz, 1H), 7.19 (s, 1H), 4.42 - 4.38 (m, 1H), 4.28 - 4.20 (m, 1H), 3.83 (s, 3H),
3.58 - 3.49 (m, 1H), 3.11 (s, 3H), 1.90 - 1.82 (m, 1H), 1.68 - 1.62 (m, 1H), 1.58
- 1.53 (m, 1H), 1.10 -1.00 (m, 6H).
Example 76
(S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(methylsulfonyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0465]

Part A. (S)-2-(1-(4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione
[0466] (S)-
tert-Butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (300 mg, 0.683 mmol) was
taken up in AcOH (15 mL) and treated with periodic acid (156 mg, 0.683 mmol), and
H
2SO
4 (0.018 mL, 0.341 mmol). The reaction mixture was heated to 80 °C and maintained for
20 min after which iodine (104 mg, 0.410 mmol) was added and heating was continued
at 80 °C for an additional 3 h. After cooling, the volatiles were exaporated and the
residue was taken up in with ethyl acetate (25 mL). The organic layer was washed with
saturated aqueous NaHCO
3 (10 mL), then brine (10 mL), dried over Na
2SO
4, filtered and concentrated under reduced pressure to afford
(S)-2-(1-(4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione (300mg, 0.61
mmol, 90% crude yield) as a brown solid. The material was taken to the next step without
further purification. LC/MS (ESI) m/e 466.1 [(M+H)
+, calcd for C
20H
25IN
3O
2 466.1] LC/MS retention time (method D):
tR = 0.58 min.

Part B. (S)-tert-butyl 1-(9-iodo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0467] Prepared as described in Example 15, Part C to afford
(S)-tert-butyl 1-(9-iodo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate (300 mg, 0.531 mmol, 82%
yield) as a red-orange solid. LC/MS (ESI) m/e 566.5 [(M+H)
+, calcd for C
25H
33IN
3O
4 566.2]; LC/MS retention time (method E):
tR = 1.27 min.

Part C. (S)-tert-butyl 1-(4,6-dimethyl-9-(methylsulfonyl)-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0468] (S)-tert-butyl (1-((9-iodo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (100 mg, 0.177 mmol), L-proline
(20.36 mg, 0.177 mmol), methanesulfinic acid, sodium salt (181 mg, 1.769 mmol),NaOH
(11.32 mg, 0.283 mmol) and copper(I) iodide (33.7 mg, 0.177 mmol) were taken up in
DMSO (5 mL) and purged with nitrogen gas for 5 min. The resultant mixture was sealed
in a microwave tube and heated at100 °C in a microwave for 2.5h. The reaction mixture
was cooled to room temperature, treated with ice-cold water (5 mL) and extracted with
ethyl acetate (3x5 mL). The combined organic layers were dried over sodium sulfate,
filtered and concentrated under reduced pressure to afford
(S)-tert-butyl 1-(4,6-dimethyl-9-(methylsulfonyl)-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate (150 mg, 0.07 mmol, 39 %
crude yield, 24 % purity) as a black gummy solid. The material was taken to the next
step with out purification. LC/MS (ESI) m/e 518.2 [(M+H)
+, calcd for C
26H
36N
3O
6S 518.2] LC/MS retention time (method B):
tR = 1.51 min.

Part D. (S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(methylsulfonyl)benzo[c][2,7]naphthyridin-5(6H)-one
[0469] Prepared as in Example 2, Part E to afford
(S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(methylsulfonyl)benzo[
c][2,7]naphthyridin-5(
6H)-one (4 mg, 0.009 mmol, 13% yield) as an off-white solid. LC/MS (ESI) m/e 466.1 [(M+H)
+, calcd for C
20H
25IN
3O
2 466.1]; LC/MS retention time (method D):
tR = 0.58 min. HPLC retention time (method):
tR = min and HPLC retention time (method):
tR =min.
1H NMR (400 MHz,
CD3OD) δ ppm - 8.85 (s 1 H), 8.65 (d,
J = 6 Hz, 1 H), 8.25 (d,
J = 6 Hz, 1 H), 7.25 (s, 1 H), 4.65 (m, 1 H), 4.32 (m, 1 H), 3.85 (s, 4 H), 3.1 (s,
3H), 1.93 (s, 3 H), 1.92 (m, 1 H), 1.65 (m, 2 H), 1.01 (m, 6 H).
Example 77
(S)-8-(2-amino-4-methylpentyloxy)-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0470]

[0471] To a solution of
(S)-tert-butyl (1-((6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (500 mg, 0.192 mmol) (prepared
as described in Example 49), in acetonitrile (5 mL) and water (5 mL) was added ceric
ammonium nitrate (527 mg, 0.962 mmol). The reaction mixture was stirred for 5 h at
room temperature. The reaction mixture was diluted with ethyl acetate (5 mL) and water
(5 mL). The organic layer was separated, dried with sodium sulfate and concentrated
under reduced pressure. The residue was purified by silica gel chromatography (1:1
ethyl acetate : hexane) to afford
(S)-8-(2-amino-4-methylpentyloxy)-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (100 mg, 0.154 mmol, 80% yield) as an off-white solid. LC/MS (ESI) m/e 326.2
[(M+H)
+, calcd for C
19H
24N
3O
2 326.2] LC/MS retention time (method C):
tR = 1.56 min. HPLC retention time (method A):
tR = 6.98 min; HPLC retention time (method B):
tR = 6.96 min.
1H NMR (400 MHz,
CD3OD) δ ppm 6.32 (m, 1 H), 8.44 (m, 2 H), 7.13 (m, 1 H), 6.94 (d, J = 2.4 Hz, 1 H), 4.4
(m, 1 H), 4.3 (m, 1 H), 3.75 (m, 1 H), 3.2 (s, 3 H), 1.75 (m, 3 H), 1.10 (m, 6 H).
Example 78
(R)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carbonitrile
[0472]

Part A. (R)-tert-butyl 1-(4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0473] Buchwald coupling performed as described in Example 16, Part H to afford title compound
(900 mg, 1.58 mmol, 54% yield, 77% purity) as an off-white solid. LC/MS (ESI) m/e
440.3 [(M+H)
+, calcd for C
25H
34N
3O
4 440.2] LC/MS retention time (method D):
tR = 0.89 min.

Part B. (R)-tert-butyl 1-(9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0474] Prepared as described in Example 3, Part A to afford title compound (750 mg, 0.94
mmol, 79% yield, 65% purity) as an orange red solid. LC/MS (ESI) m/e 518.2 [(M+H)
+, calcd for C
25H
33BrN
3O
4 518.2] LC/MS retention time (method D):
tR = 0.92 min.

Part C. (R)-tert-butyl 1-(9-cyano-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0475] Prepared as described in Example 64, Part B to afford title compound (300 mg, 0.18
mmol, 47% yield, 28% purity) as a black gum. LC/MS (ESI) m/e 465.2 [(M+H)
+, calcd for C
26H
33N
4O
4 465.2] LC/MS retention time (method C):
tR = 2.74 min.

Part D. (R)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carbonitrile
[0476] Prepared as described in Example 2, Part E to afford title compound (20 mg, 0.051
mmol, 59% yield, 93% purity) as a yellow solid. LC/MS (ESI) m/e 365.2 [(M+H)
+, calcd for C
21H
25N
4O
2 365.2] LC/MS retention time (method C):
tR = 2.10 min. HPLC retention time (method A): t
R = 8.35 min and HPLC retention time (method B): t
R = 9.17 min.
1H NMR (400MHz, METHANOL-d
4) δ ppm 8.98 (s, 1H), 8.71 (d,
J=6.3 Hz, 1H), 8.53 (d,
J=6.5 Hz, 1H), 7.23 (s, 1H), 4.65 (dd,
J=10. 7, 3.1 Hz, 1H), 4.50 (dd,
J=10.8, 6.0 Hz, 1H), 3.85 (br. s., 1H), 3.84 (s, 3H), 3.20 (s, 3H), 1.92 - 1.80 (m,
2H), 1.78 - 1.66 (m, 1H), 1.09 (d,
J=1.8 Hz, 3H), 1.07 (d,
J=1.5 Hz, 3H).
Example 79
(S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-6-(2-methoxyethyl)-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0477]

Part A: 4-(4-chloro-2-fluorophenyl)-N-(2-methoxyethyl)-2-methylnicotinamide
[0478] A solution of 4-(4-chloro-2-fluorophenyl)-2-methylnicotinic acid (2g, 5.19 mmol),
prepared as described in Example 16, Part E, in thionyl chloride (5 mL, 68.5 mmol)
was heated at 70 °C for 2 h. After cooling, the volatiles were removed under reduced
pressure. The residue was dissolved in 4 mL of anhydrous DCM and added to a pre-cooled
solution of 2-methoxyethanamine (0.390 g, 5.19 mmol) and triethyl amine (3.62 mL,
26.0 mmol) in DCM (8 mL) at 0 °C. The resulting reaction mixture was stirred at rt
for 4 h. Water (30 mL) was then added and the solution was extracted with DCM (2 x
20 mL). The combined organic layers were washed with brine (20 mL), dried over sodium
sulphate, and concentrated under erduced pressure. The residue was purified by silica
gel chromatography using a gradient of EtOAc and hexane as eluant to yield 4-(4-chloro-2-fluorophenyl)-
N-(2-methoxyethyl)-2-methylnicotinamide (1.3 g, 2.88 mmol, 56% yield) as a yellow oil.
LC/MS (ESI) m/e 323.1 [(M+H)
+, calcd for C
16H
17ClFN
2O
2 323.1]; LC/MS retention time (method D):
tR = 0.61 min.

Part B: 8-chloro-6-(2-methoxyethyl)-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0479] 4-(4-Chloro-2-fluorophenyl)-
N-(2-methoxyethyl)-2-methylnicotinamide was subjected to a cyclization reaction as described
in Example 2, Part C to yield 8-chloro-6-(2-methoxyethyl)-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (1.12 g, 2.55 mmol, 89 % yield) as a white solid. LC/MS (ESI) m/e 303.2 [(M+H)
+, calcd for C
16H
16ClN
2O
2 303.1]; LC/MS retention time (method B):
tR = 1.38 min.

Part C: (S)-tert-butyl (1-((6-(2-methoxyethyl)-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0480] 8-Chloro-6-(2-methoxyethyl)-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one was subjected to ether synthesis as described Example 16, Part H to afford
(S)-tert-butyl (1-((6-(2-methoxyethyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (511 mg, 0.723 mmol, 53%
yield) as a white solid. LC/MS (ESI) m/e 484.6 [(M+H)
+, calcd for C
27H
18N
3O
5 484.3]; LC/MS retention time (method E):
tR = 1.17 min.

Part D: (S)-tert-butyl (1-((9-chloro-6-(2-methoxyethyl)-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0481] (S)-
tert-Butyl (1-((6-(2-methoxyethyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate was subjected to chlorination
as described in Example 41, Part A to afford
(S)-tert-butyl (1-((9-chloro-6-(2-methoxyethyl)-4-methyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (260 mg, 0.227 mmol, 80
% crude yield) as a brown solid. LC/MS (ESI) m/e 518.2 [(M+H)
+, calcd for C
27H
37ClN
3O
5 518.2]; LC/MS retention time (method D):
tR = 0.91 min; HPLC retention time (method B):
tR = 1.84 min.

Part E: (S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-6-(2-methoxyethyl)-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0482] (S)-
tert-Butyl (1-((9-chloro-6-(2-methoxyethyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate was subjected Boc-deprotection
as described in Example 2, Part E to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-6-(2-methoxyethyl)-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one, 2 HCl (11.23 mg, 0.021 mmol, 48% yield) as a yellow solid. LC/MS (ESI) m/e
418.2 [(M+H)
+, calcd for C
22H
29ClN
3O
3 418.2]; HPLC retention time (method A): t
R = 7.91 min; HPLC retention time (Method B): t
R = 9.29 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.79 - 8.66 (m, 3H), 7.51 (s, 1H), 4.70 (t,
J=4.9 Hz, 2H), 4.63 - 4.54 (m, 1H), 4.45 (dd,
J=10.4, 5.1 Hz, 1H), 3.89 - 3.86 (m, 3H), 3.38 (s, 3H), 3.28 (s, 3H), 1.91 - 1.81 (m,
2H), 1.80 - 1.69 (m, 1H), 1.11 - 1.08 (m, 3H), 1.07 (br. s., 3H).
Example 80
(S)-8-((2-amino-4-methylpentyl)oxy)-6-(2-methoxyethyl)-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0483]

[0484] Boc-deprotection of
(S)-tert-butyl (1-((6-(2-methoxyethyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate, (prepared as described
in Example 79, Part C) was carried out as described in Example 2, Part E to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-6-(2-methoxyethyl)-4 methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (31.3 mg, 0.081 mmol, 77% yield) as a white solid. LC/MS (ESI) m/e 384.2 [(M+H)
+, calcd for C
22H
30N
3O
3 384.2]; LC/MS retention time (method B):
tR = 1.06 min; HPLC retention time (method A): t
R = 8.11 min; HPLC retention time (method B): t
R = 9.29 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.55 (d,
J=5.8 Hz, 1H), 8.36 (d,
J=9.0 Hz, 1H), 8.12 (d,
J=5.8 Hz, 1H), 7.22 (d,
J=2.3 Hz, 1H), 7.04 (dd,
J=9.0, 2.5 Hz, 1H), 4.58 (t,
J=5.8 Hz, 2H), 4.18 (dd,
J=9.4, 3.9 Hz, 1H), 4.00 (dd,
J=9.3, 7.0 Hz, 1H), 3.81 (t,
J=5.8 Hz, 2H), 3.39 (s, 3H), 3.38 - 3.36 (m, 1H), 3.08 (s, 3H), 1.91 - 1.79 (m, 1H),
1.57 - 1.40 (m, 2H), 1.04 (d,
J=6.5 Hz, 3H), 1.01 (d,
J=6.8 Hz, 3H).
Example 81
(S)-8-(2-amino-4-methylpentyloxy)-7-fluoro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0485]

Part A: (S)-tert-butyl 1-(7-fluoro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0486] Prepared as described in Example 16, Part H from 8-bromo-7-fluoro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one, (prepared as described in Example 29, Part F).to afford
(S)-tert-butyl 1-(7-fluoro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate (0.013 g, 0.028 mmol, 37%
yield) as a white solid. NMR (400MHz, DMSO-
d6) δ ppm 8.64 (d,
J=7.2 Hz, 1H), 8.36 (m, 1H), 8.21 (m, 1H), 7.23 (m, 1H), 6.84 (d,
J=11.2 Hz, 1H), 6.28 (s, 1H), 4.06 (m, 2 H), 3.92 (m, 1 H), 3.78 (m, 3 H), 2.99 (s,
1 H), 1.65 (m, 1H), 1.38 (m, 11H), 0.89 (m, 6 H).

Part B: (S)-8-(2-amino-4-methylpentyloxy)-7-fluoro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0487] Prepared as described in Example 2, Part E to afford the title product (8.5 mg, 0.024
mmol, 98 % yield as a brown solid. LC/MS (ESI) m/e 358.2 [(M+H)
+, calcd for C
20H
25FN
3O
2 358.2] LC/MS retention time (method B):
tR = 3.58 min. HPLC retention time (method A):
tR = 7.68 min and HPLC retention time (method B):
tR = 8.02 min.
1H NMR (400MHz, DMSO-d
6) δ ppm 8.69 (d,
J=5.8 Hz, 1H), 8.36 (d,
J=7.5 Hz, 1H), 8.27 (d,
J=5.8 Hz, 1H), 8.07 (br. s., 2H), 7.35 - 7.24 (m, 1H), 4.38 (dd,
J=10.7, 3.4 Hz, 1H), 4.26 (dd,
J=10.8, 6.0 Hz, 1H), 3.81 (d,
J=9.3 Hz, 3H), 3.67 - 3.60 (m, 1H), 3.02 (s, 3H), 1.87 - 1.72 (m, 1H), 1.59 (td,
J=7.1, 3.9 Hz, 2H), 0.96 (d,
J=2.8 Hz, 3H), 0.94 (d,
J=2.8 Hz, 3H).
Example 82
(S)-8-(2-amino-4-methylpentyloxy)-7-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0488]

Part A. 4-(4-bromo-2,3-difluorophenyl)-N-(4-methoxybenzyl)-2-methylnicotinamide
[0489] Prepared as described in Example 29, Part E by reaction of biaryl acid (described
in Example 29, Part D) with PMB-amine to afford 4-(4-bromo-2,3-difluorophenyl)-
N-(4-methoxybenzyl)-2-methylnicotinamide (0.16 g, 0.314 mmol, 92%) as an off-white solid.
LC/MS (ESI) m/e 447.0 [(M+H)
+, calcd for C
21H
18BrF
2N
2O
2 447.1]; LC/MS retention time (method E):
tR = 0.94 min.

Part B: 8-bromo-7-fluoro-6-(4-methoxybenzyl)-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0490] Prepared as described in Example 29, Part F to afford 8-bromo-7-fluoro-6-(4-methoxybenzyl)-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.12 g, 0.269 mmol, 90%) as a off-white solid. LC/MS (ESI) m/e 429.1 [(M+2H)
+, calcd for C
21H
18BrFN
2O
2 429.0]; LC/MS retention time (method E):
tR = 1.15 min.

Part C. tert-butyl 1-(7-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-2,4-dimethylpentan-2-ylcarbamate
[0491] Prepared as described in Example 16, Part H to afford
tert-butyl 1-(7-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-2,4-dimethylpentan-2-ylcarbamate (46 mg, 0.081 mmol, 13%
yield) as an off-white solid. LC/MS (ESI) m/e 564.3 [(M+H)
+, calcd for C
32H
39FN
3O
5 564.3]; LC/MS retention time (Method H):
tR = 2.35 min.

Part D. (S)-8-(2-amino-4-methylpentyloxy)-7-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0492] Prepared as described in Example 17, Part I to afford
(S)-8-(2-amino-4-methylpentyloxy)-7-fluoro-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (8 mg, 0.023 mmol, 72% yield) as an off-white solid. LC/MS (ESI) m/e 342.2 [(M)
-, calcd for C
19H
21FN
3O
2 342.2]; LC/MS retention time (method C):
tR = 1.99 min; HPLC retention time (method B): t
R = 6.91 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.69 (d,
J=6.3 Hz, 1H), 8.44 (d,
J=6.3 Hz, 1H), 8.28 (dd,
J=9.3, 2.0 Hz, 1H), 7.26 (dd,
J=9.0, 7.8 Hz, 1H), 4.51 (dd,
J=10.7, 3.1 Hz, 1H), 4.36 (dd,
J=10.7, 6.1 Hz, 1H), 3.85 - 3.72 (m, 1H), 3.19 (s, 3H), 1.92 - 1.63 (m, 3H), 1.07 (d,
J=3.8 Hz, 3H), 1.06 (d,
J=3.8 Hz, 3H).
Example 83
(S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(thiazol-5-yl)benzo[c][2,7]naphthyridin-5(6H)-one
[0493]

Part A. (S)-tert-butyl 1-(4,6-dimethyl-5-oxo-9-(thiazol-5-yl)-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0494] 5-Bromothiazole (0.050 g, 0.305 mmol) and hexamethyltin (0.158 mL, 0.762 mmol) were
taken up in 1,4-dioxane (1 mL) and purged with nitrogen for 10 min. Tetrakis (triphenylphosphine)palladium
(0.035 g, 0.030 mmol) was added and the reaction mixture was stirred for 2 h at rt.
(S)-
tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6 dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.158 g, 0.305 mmol) and
lithium chloride (0.013 g, 0.305 mmol) were added and the mixture was purged with
N
2 for 10min. The reaction mixture was then heated for 16 h at 90 °C. After cooling,
the reaction mixture was filtered through diatomaceous earth (Celite
®) and concentrated under reduced pressure. The residue was purified by preparative
HPLC to afford
(S)-
tert-butyl 1-(4,6-dimethyl-5-oxo-9-(thiazol-5-yl)-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate (40 mg, 0.053 mmol, 18% yield)
as a yellow solid. LC/MS (ESI) m/e 23.6 [(M+H)
+, calcd for C
28H
15N
4O
4S 523.2]; LC/MS retention time (method E):
tR = 1.09 min.

Part B. (S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(thiazol-5-yl)benzo[c][2,7]naphthyridin-5(6H)-one
[0495] Prepared as described in Example 2, Part E to afford
(S)-8-(2-amino-4-methylpentyloxy)-4,6-dimethyl-9-(thiazol-5-yl)benzo[
c][2,7]naphthyridin-5(
6H)-one (16 mg, 0.037 mmol, 80 % yield) as an off-white solid. LC/MS (ESI) m/e 423.2
[(M+H)
+, calcd for C
23H
27N
4O
2S 423.2]; LC/MS retention time (method C):
tR = 2.04 min; HPLC retention time (method A): t
R = 9.1 min; retention time (method B): t
R = 9.72 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 9.10 (s, 1H), 8.73 (s, 1H), 8.61 (d,
J=5.8 Hz, 1H), 8.49 (s, 1H), 8.30 (d,
J=5.8 Hz, 1H), 7.16 (s, 1H), 4.38 (dd,
J=
9.5, 4.0 Hz, 1H), 4.25 (dd,
J=9.5, 6.5 Hz, 1H), 3.82 (s, 3H), 3.59 - 3.51 (m, 1H), 3.10 (s, 3H), 1.91 - 1.82 (m,
1H), 1.69 - 1.46 (m, 2H), 1.04 (d,
J=5.5 Hz, 3H), 1.03 (d,
J=5.8 Hz, 3H).
Example 84
(S)-methyl 8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carboxylate
[0496]

Part A: (S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carboxylic acid
[0497] To a flask containing
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carbonitrile (60 mg, 0.165 mmol), (prepared as described in
Example 64) was added concentrated HCl (5 mL). The resultant mixture was heated to
80 °C for 12 h. After cooling, the volatiles were removed under reduced pressure to
afford
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carboxylic acid (40 mg, 0.104 mmol, 63% cude yield) as a yellow
solid. The material was carried on without further purification. LC/MS (ESI)
m/
e 384.1 [(M+H)
+, calcd for C
21H
26N
3O
4 384.2]; LC/MS retention time (method D):
tR = 0.71 min.

Part B: (S)-methyl 8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carboxylate
[0498] To a flask containing
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carboxylic acid (40 mg, 0.104 mmol) in MeOH (3 mL) at 0 °C was
added SOCl
2 (0.076 mL, 1.043 mmol) dropwise. The resultant solution was heated to 70 °C for 12
h. After cooling, the volatiles were removed under reduced pressure. The residue was
purified by prep HPLC (using 0.1% TFA ACN : water) to afford
(S)-methyl 8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carboxylate, 2 TFA (1.65 mg, 2.427 µmol, 2% yield) as pale brown
solid. LC/MS (ESI)
m/
e 398.2 [(M+H)
+, calcd for C
22H
28N
3O
4 398.2]; LC/MS retention time (method C):
tR = 1.58 min; HPLC retention time (method A):
tR = 9.14 min; HPLC retention time (method B):
tR = 9.58 min;
1H NMR (400MHz, METHANOL-d
4) δ ppm 9.01 (s, 1H), 8.68 (d,
J=6.0 Hz, 1H), 8.40 (d,
J=6.0 Hz, 1H), 7.23 (s, 1H), 4.69 (dd,
J=10.0, 3.0 Hz, 1H), 4.36 (dd,
J=10.5, 7.0 Hz, 1H), 4.02 (s, 3H), 3.88 -3.81 (m, 4H), 3.16 (s, 3H), 1.93 - 1.65 (m,
3H), 1.09 (d,
J=4.0 Hz, 3H), 1.07 (d,
J=4.0 Hz, 3H).
Example 85
(S)-8-((2-amino-4-methylpentyl)oxy)-1-fluoro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0499]

Part A: methyl 4-chloro-5-fluoronicotinate
[0500] To a solution of 4-chloro-5-fluoronicotinic acid (1.7 g, 9.68 mmol) in acetonitrile
(18 mL) cooled to 0 °C was added DBU (3.65 mL, 24.21 mmol) dropwise. The reaction
mixture was stirred for 30 min. To this mixture iodomethane (3.03 mL, 48.4 mmol) was
added dropwise and stirred at rt for 12 h. The volatiles were removed under reduced
pressure. The residue was purified via silica gel column chromatography (hexane and
ethyl acetate) to afford methyl 4-chloro-5-fluoronicotinate (1.2 g, 6.33 mmol, 65%
yield) as a yellow solid. LC/MS (ESI) m/e 190.0 [(M+H)
+, calcd for C
7H
6ClFNO
2 189.9]; LC/MS retention time (method D):
tR = 0.77 min.

Part B: Methyl 4-(4-chloro-2-fluorophenyl)-5-fluoronicotinate
[0501] To a solution of methyl 4-chloro-5-fluoronicotinate (1.2 g, 6.33 mmol) in 1,4-dioxane
(12 mL) and water (0.5 mL) was added (4-chloro-2-fluorophenyl)boronic acid (1.214
g, 6.96 mmol). The mixture was then purgend with nitrogen gas for 5 min. Potassium
phosphate, dibasic (2.205 g, 12.66 mmol) and PdCl
2(dppf) (0.371 g, 0.506 mmol) were added and again the mixture was purged with N
2 for 5 min.The reaction ixture was heated to 80 °C for 12 h. After cooling, water
was added to and the mixture was extracted with ethyl acetate (3x25 mL). The combined
organic layers were washed with brine, dried over sodium sulfate and concentrated
under reduced pressure. The residue was purified by silica gel chromatography using
hexane and ethyl acetate to afford methyl 4-(4-chloro-2-fluorophenyl)-5-fluoronicotinate
(900 mg, 3.17 mmol, 50% yield) as a yellow solid. LC/MS (ESI) m/e 284.0 [(M+H)
+, calcd for C
13H
9ClF
2NO
2 284.02]; LC/MS retention time (method D):
tR = 1.01 min.

Part C: 4-(4-chloro-2-fluorophenyl)-5-fluoronicotinic acid
[0502] To the solution of methyl 4-(4-chloro-2-fluorophenyl)-5-fluoronicotinate (600 mg,
2.115 mmol) in tetrahydrofuran (2.5 mL), MeOH (2.5 mL) and water (2.5 mL) was added
LiOH (50.7 mg, 2.115 mmol) and the mixture was stirred at rt for 12 h. The volatiles
were removed and the residue was diluted with water. The pH was adjusted to 4 with
1.5N HCl. The product was extracted with ethyl acetate (2x5 mL). The combined organic
layers were dried over sodium sulfate and concentrated under reduced pressure to afford
4-(4-chloro-2-fluorophenyl)-5-fluoronicotinic acid (530 mg, 1.966 mmol, 93 % crude
yield) the pale brown solid. The material was carried on without further purification.
LC/MS (ESI) m/e 269.9 [(M+H)
+, calcd for C
12H
7ClF
2NO
2 270.0]; LC/MS retention time (method D):
tR = 0.88 min.

Part D: 4-(4-chloro-2-fluorophenyl)-5-fluoro-N-methylnicotinamide
[0503] To the solution of 4-(4-chloro-2-fluorophenyl)-5-fluoronicotinic acid (530mg, 1.966
mmol) in DMF (5 mL) cooled at 0 °C, was added HOBT (602 mg, 3.93 mmol) and EDC (565
mg, 2.95 mmol), then the mixture was stirred for 5 min. Methylamine hydrochloride
(531 mg, 7.86 mmol) and DIEA (1.030 mL, 5.90 mmol) were added and the resultant mixture
was stirred at RT for 12 h. Ice-cold water was added to the reaction and the solid
obtained was collected by vacuum filtration. The solid so obtained was washed with
water (50 mL) and air dried to afford 4-(4-chloro-2-fluorophenyl)-5-fluoro-
N-methylnicotinamide (350 mg, 1.238 mmol, 63 % yield) as an orange oil. LC/MS (ESI)
m/e 282.9 [(M+H)
+, calcd for C
13H
10ClF
2N
2O 283.0]; LC/MS retention time (method D):
tR = 0.83 min.

Part E: 8-chloro-1-fluoro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0504] 4-(4-Chloro-2-fluorophenyl)-5-fluoro-
N-methylnicotinamide was subjected to cyclization as described in Example 2 and Part
C to afford 8-chloro-1-fluoro-6-methylbenzo[c][2,7]naphthyridin-5(
6H)-one (85 mg, 0.320 mmol, 60% yield) as a white solid. LC/MS (ESI) m/e 263.0 [(M+H)
+, calcd for C
13H
9ClFN
2O 263.0]; LC/MS retention time (method C):
tR = 1.77 min.

Part F: (S)-tert-butyl (1-((1-fluoro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0505] 8-Chloro-1-fluoro-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one was subjected to ether synthesis as described in Example 16, Part H to afford
(S)-tert-butyl (1-((1-fluoro-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (60 mg, 0.135 mmol, 71%
yield) as an off white solid. LC/MS (ESI) m/e 444.2 [(M+H)
+, calcd for C
24H
31FN
3O
4 445.2]; LC/MS retention time (method D):
tR = 1.11 min.

Part G: (S)-8-((2-amino-4-methylpentyl)oxy)-1-fluoro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0506] (S)-
tert-Butyl (1-((1-fluoro-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate was subjected to Boc-deprotection
as described in Example 2, Part E. The crude product was purified by preparative HPLC
using 0.1%TFA ACN:water to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-1-fluoro-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one, TFA (42.68 mg, 0.091 mmol, 95 % yield) as a yellow solid. LC/MS (ESI) m/e 344.2
[(M+H)
+, calcd for C
19H
23FN
3O
2 344.2]; LC/MS retention time (method C):
tR = 2.07 min; HPLC retention time (method A): t
R = 5.52 min; HPLC retention time (method B): t
R = 6.63 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 9.38 (s, 1H), 8.77 (d,
J=5.0 Hz, 1H), 8.67 (dd,
J=9.0, 3.0 Hz, 1H), 7.21 (d,
J=2.0 Hz, 1H), 7.16 (dq,
J=9.1, 1.3 Hz, 1H), 4.48 (dd,
J=10.5, 3.0 Hz, 1H), 4.29 (dd,
J=10.5, 6.0 Hz, 1H), 3.82 (s, 3H), 3.80 - 3.73 (m, 1H), 1.94 - 1.82 (m, 1H), 1.82 -
1.63 (m, 2H), 1.08 (d,
J=4.0 Hz, 3H), 1.07 (d,
J=4.0 Hz, 3H).
Example 86
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-9-(pyridin-2-yl)benzo[c][2,7]naphthyridin-5(6H)-one
[0507]

Part A. (S)-tert-butyl (1-((4,6-dimethyl-5-oxo-9-(pyridin-2-yl)-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0508] To a solution of
(S)-tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (100 mg, 0.193 mmol) in
1,4-dioxane (2 mL) was added 2-(tributylstannyl)pyridine (85 mg, 0.231 mmol) and Pd(PPh
3)
4 (11.14 mg, 9.64 µmol). The reaction mixture was degassed for 30 min and heated to
120 °C for 1 h in a microwave. The reaction mixture was cooled and diluted with water
(10 mL) and extracted with ethyl acetate (3 x 10 mL). The combined organic layers
were dried over sodium sulfate and concentrated under reduced pressure. The crude
product was purified by silica gel chromatography (3% methanol in chloroform) to afford
(S)-tert-butyl (1-((4,6-dimethyl-5-oxo-9-(pyridin-2-yl)-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (50 mg, 0.120 mmol, 62%
yield) as a pale yellow solid which was carried on without further purification LC/MS
(ESI) m/e 517.7 [(M+H)
+, calcd for C
30H
37N
4O
4 517.3]; LC/MS retention time (method E):
tR = 1.19 min.

Part B. (S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-9-(pyridin-2-yl)benzo[c][2,7]naphthyridin-5(6H)-one
[0509] To a solution of
(S)-tert-butyl (1-((4,6-dimethyl-5-oxo-9-(pyridin-2-yl)-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (35 mg, 0.068 mmol) in
Methanol (4 mL) was added HCl in 1,4-dioxane (0.169 mL, 0.677 mmol) at 0 °C. Then
the reaction mixture was stirred at RT for 2 h. The volatiles were concentrated under
reduced pressure. The residue so obtained was basified with saturated aqueous NaHCO
3, diluted with water and extracted with DCM (3 x 5 mL). The combined organic layers
were dried over Na
2SO
4 and concentrated in
vacuo. The crude product was purified by reverse phase prep HPLC (Sunfire C18 column (19.0
x 150 mm) 10.0 micron; mobile phase A: 10 mM ammonium acetate in water; mobile phase
B: acetonitrile; flow rate: 16.0 mL) to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-9-(pyridin-2-yl)benzo[
c][2,7]naphthyridin-5(
6H)-one (10 mg, 0.024 mmol, 35% yield) as an off-white solid. LC/MS (ESI) m/e 417.6
[(M+H)
+, calcd for C
25H
29N
4O
2 417.2]; LC/MS retention time (method E):
tR = 0.84 min; HPLC retention time (method A): t
R = 7.61 min; HPLC retention time (method B): t
R = 8.29 min;
1H NMR (400MHz, METHANOL-
d4).
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.70 (d,
J=4.3 Hz, 1H), 8.64 (s, 1H), 8.58 (d,
J=5.5 Hz, 1H), 8.21 (d,
J=5.8 Hz, 1H), 8.04 - 7.94 (m, 1H), 7.93 - 7.86 (m, 1H), 7.46 (ddd,
J=7.3, 5.0, 1.3 Hz, 1H), 7.18 (s, 1H), 4.32 (dd,
J=9.5, 4.3 Hz, 1H), 4.13 (dd,
J=9.4, 6.7 Hz, 1H), 3.84 (s, 3H), 3.36 - 3.34 (m, 1H), 3.11 (s, 3H), 1.86 - 1.70 (m,
1H), 1.53 - 1.32 (m, 2H), 0.97 (d,
J=6.8 Hz, 3H), 0.93 (d,
J=6.5 Hz, 3H).
Example 87 and Example 88
(S)-8-((2-amino-5,5,5-trifluoro-4-methylpentyl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one; diastereomers 1 and 2
[0510]

Part A. ethyl 2-amino-5,5,5-trifluoro-4-methylpentanoate hydrochloride
[0511] To 2-amino-5,5,5-trifluoro-4-methylpentanoic acid (50 mg, 0.270 mmol) in a flask
was added hydrochloric acid 2N in ethanol (1350 µl, 5.40 mmol). The solution was refluxed
at 80 °C for 5 h. After cooling, the ethanol was removed under reduced pressure. The
residue was triturated with diethyl ether (2x). The solid so obtained (60 mg, 0.240
mmol) was taken up in dichloromethane (5 mL). To this suspension cooled to 0°C was
added triethylamine (0.167 mL, 1.202 mmol) and di-
tert-butyl carbonate (0.054 mL, 0.312 mmol). The reaction mixture was allowed to warm
to room temperature and stirred for 12 h. The reaction mixture was diluted with water
(10 mL) and extracted with ethyl acetate (3 x 10 mL). The combined organic layers
were dried over sodium sulfate and concentrated under reduced pressure to afford ethyl
2-((
tert-butoxycarbonyl)amino)-5,5,5-trifluoro-4-methylpentanoate (55 mg, 0.176 mmol, 73% crude
yield) as a white solid. The material was carried on without further purification.
GCMS (ESI) m/e 212 [(M)
-, calcd for C
8H
13F
3NO
2 212] GC/MS (Method: Agilent GCMS Module-7890 (GC) 5975C(MSD) HP-5MS, 30m x 0.25mm
ID x 0.25u Film thickness 0.9 mL/min at constant flow of Helium) retention time
tR = 6.38 min.

Part B. Tert-butyl (5,5,5-trifluoro-1-hydroxy-4-methylpentan-2-yl)carbamate
[0512] To the solution of ethyl 2-((
tert-butoxycarbonyl)amino)-5,5,5-trifluoro-4-methylpentanoate (500 mg, 1.596 mmol) in
ethanol (2 mL) at 0 °C was added NaBH
4 (604 mg, 15.96 mmol). The reaction mixture was allowed to stir at RT for 16 h. The
reaction mixture was quenched with aqueous ammonia. The solutiom was filter through
a glass funnel and the resulting filtrate was concentrated to afford the
tert-butyl (5,5,5-trifluoro-1-hydroxy-4-methylpentan-2-yl)carbamate (400 mg, 1.475 mmol,
92 % crude yield) as a colorless gummy semisolid material. The material was carried
on without further purification. LC/MS (ESI) m/e 172.1 [(M+H)
+, calcd for C
6H
13F
3NO 172.1] LC/MS retention time (Method A):
tR = 2.1 min.

Part C: Tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-5,5,5-trifluoro-4-methylpentan-2-yl)carbamate
[0513] 8-Chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one and
tert-butyl (5,5,5-trifluoro-1-hydroxy-4-methylpentan-2-yl)carbamate was subjected to ether
synthesis as described in Example 16, Part H. The compound was purified by reverse
phase HPLC (Sunfire C18 (250 x 30 mm,10µm) column; mobile phase A: 10 mM ammonium
acetate in water; mobile phase B: acetonitrile; flow rate: 25 mL) to afford the product
as a off-white solid. The diasteromeric mixture so obtained was subjected to diastereomeric
separation by normal phase chiral prep HPLC column: IC (250 x 30 mm, 5µm); mobile
phase A: 0.2 % DEA : hexane; mobile phase B: Ethanol; flow rate: 16 mL / min) to afford
tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-5,5,5-trifluoro-4-methylpentan-2-yl)carbamate as two
diastereomeric mixtures (1 and 2). The absolute sterochemistry of the diasteromers
was not determined.
Diastereomeric mixture 1: (30 mg, 0.061 mmol, 10% yield) as an off-white solid. LC/MS of Diastereomeric mixture
(ESI) m/e 494.3 [(M+H)
+, calcd for C
25H
31F
3N
3O
4 494.2]; LC/MS retention time (Method C)
tR = 2.17 min.
Diastereomeric mixture 2: (80 mg, 0.162 mmol, 26% yield) as an off-white solid. LC/MS of Diastereomeric mixture
(ESI) m/e 494.2 [(M+H)
+, calcd for C
25H
31F
3N
3O
4 494.2]; LC/MS retention time (Method C)
tR = 2.16 min.

Part D: 8-((2-amino-5,5,5-trifluoro-4-methylpentyl)oxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one: (Diastereomer 2)
[0514] Diastereomeric mixture 1 (30 mg, 0.061 mmol) was subjected to Boc deprotection as
described in Example 2, Part E to afford 8-((2-amino-5,5,5-trifluoro-4-methylpentyl)oxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (72.3 mg, 0.172 mmol, 99% yield) as an off white solid. LC/MS (ESI) m/e 394.6
[(M+H)
+, calcd for C
20H
23F
3N
3O
2 394.2]; HPLC retention time (method A): t
R = 8.62 min; HPLC retention time (method B): t
R = 8.77 min;
1H NMR (400MHz, DMSO-d
6) δ ppm 8.62 (d,
J=
5.5 Hz, 1H), 8.44 (d,
J=8.8 Hz, 1H), 8.19 (d,
J=5.8 Hz, 1H), 7.08 - 6.92 (m, 2H), 4.11 - 3.90 (m, 2H), 3.67 (s, 3H), 3.01 (s, 3H),
3.17 - 3.10 (m, 1H), 1.96 - 1.82 (m, 1H), 1.66 - 1.48 (m, 2H), 1.10 (d,
J=6.8 Hz, 3H). Boc-protected Diastereomeric mixture 2 (80 mg, 0.162 mmol) was subjected
to Boc deprotection as described in Example 2, Part E to afford 8-((2-amino-5,5,5-trifluoro-4-methylpentyl)oxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (10 mg, 0.025 mmol, 50 % yield) as an off white solid. LC/MS (ESI) m/e 394.6
[(M+H)
+, calcd for C
20H
23F
3N
3O
2 394.2]; HPLC retention time (method A): t
R = 8.75 min; HPLC retention time (method B): t
R = 8.8 min;
1H NMR (400MHz, CHLOROFORM-d) δ ppm 8.64 (d,
J=5.5 Hz, 1H), 8.16 (d,
J=8.8 Hz, 1H), 7.83 (d,
J=5.8 Hz, 1H), 6.89 (dd,
J=8.8, 2.3 Hz, 1H), 6.85 (d,
J=2.3 Hz, 1H), 4.05 (dd,
J=9.0, 4.0 Hz, 1H), 3.89 (dd,
J=8.8, 6.5 Hz, 1H), 3.73 (s, 3H), 3.40 - 3.34 (m, 1H), 3.16 (s, 3H), 2.60 - 2.42 (m,
1H), 1.98 (dt,
J=
14.3, 6.1 Hz, 1H), 1.50 - 1.40 (m, 1H), 1.23 (d,
J=7.0 Hz, 3H).
Example 89
(S)-8-((2-amino-4-methylpentyl)oxy)-9-methoxy-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0515]

Part A. 8-chloro-9-iodo-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0516] To a stirred solution of 8-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(
6H)-one (1.0 g, 3.87 mmol) in acetic Acid (25 mL) was added H
2SO
4 (0.206 mL, 3.87 mmol) followed by periodic acid (0.881 g, 3.87 mmol). The mixture
was then heated to 80 °C for 20 min. I
2 (0.294 g, 1.160 mmol) was then added at 80 °C and stirred for 120 min. After cooling
to ambient temperature, the acetic acid was removed under reduced pressure. The residue
was neutralized with 70 mL of saturated aqueous sodium bicarbonate solution. The solid
so obtained was collected by vacuum filtration and air dried to afford 8-chloro-9-iodo-4,6-dimethylbenzo[
c][2,7]naphthyridin-5
(6H)-one (1.3 g, 3.21 mmol, 83 % yield) as a brown solid. LC/MS (ESI) m/e 385.1 [(M+H)
+, calcd for C
14H
11ClIN
2O 384.9]; LC/MS retention time (method E):
tR = 1.09 min;
1H NMR (400 MHz, DMSO-
d6) δ ppm 8.96 (s, 1 H) 8.69 (d, J=5.58 Hz, 1 H) 8.36 (d,
J=5.52 Hz, 1 H) 7.76 (s, 1 H) 3.63 (s, 3 H) 3.00 (s, 3 H).

Part B. 8-chloro-9-hydroxy-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0517] To the stirred solution of 8-chloro-9-iodo-4,6-dimethylbenzo[
c][2,7]naphthyridin-5
(6H)-one (1.0 g, 2.60 mmol) in DMSO (5 mL) and Water (5 mL) in an inert atmosphere were
added copper(I) iodide (0.050 g, 0.260 mmol) followed by 1,10-phenanthroline (0.047
g, 0.260 mmol) and KOH (2.188 g, 39.0 mmol). The reaction mixture was heated to 100
°C for 16 h and monitored by LC/MS. Upon completion, the reaction mixture was cooled
and pH adjusted to between 3 to 4 with 1 N HCl. The reaction mixture was diluted with
50 mL of water and extracted with 80 mL of dichloromethane. The organic layer was
separated, washed with brine, dried over Na
2SO
4 and concentrated under reduced pressure to afford 8-chloro-9-hydroxy-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.6 g, 2.053 mmol, 79% crude yield) as a green solid. The material was carried
on without further purification. LC/MS (ESI) m/e 273.0 [(M)
-, calcd for C
14H
10ClN
2O
2 273.05]; LC/MS retention time (method C):
tR = 2.06 min.

Part C. 8-chloro-9-methoxy-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0518] To the stirred solution of 8-chloro-9-hydroxy-4,6-dimethylbenzo[
c][2,7]naphthyridin-5
(6H)-one (0.3 g, 1.092 mmol) in DMF (10 mL) cooled to 0 °C, was added NaH (0.052 g, 2.184
mmol) followed by methyl iodide (0.205 mL, 3.28 mmol). The resultant mixture was allowed
to stir at ambient temperature for 10 h. The reaction mixture was then diluted with
water (50 mL) and extracted with ethyl acetate (2x80 mL). The combined organic layers
were separated, washed with brine, dried over Na
2SO
4 and concentrated under reduced pressure. The crude product was purified by silica
gel column chromatography using 70% ethyl acetate in petroleum ether to afford 8-chloro-9-methoxy-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.12 g, 0.416 mmol, 38% yield) as a semi-solid. LC/MS (ESI) m/e 288.4 [(M)
+, calcd for C
15H
13ClN
2O
2 288.1]; LC/MS retention time (Method A):
tR = 1.9 min.

Part D. (S)-tert-butyl (1-((9-methoxy-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0519] 8-Chloro-9-methoxy-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one was subjected to ether synthesis as described in Example 16, Part H to afford
(S)-tert-butyl (1-((9-methoxy-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (90 mg, 0.073 mmol, 18%
yield) as a semi solid. LC/MS (ESI) m/e 470.3 [(M+H)
+, calcd for C
26H
36N
3O
5 470.5]; LC/MS retention time (method D)
tR = 0.87 min.

Part E. (S)-8-((2-amino-4-methylpentyl)oxy)-9-methoxy-4,6-dimethylbenzo[c][2,7]naphthyridin-5 (6H)-one
[0520] (S)-
tert-Butyl (1-((9-methoxy-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate was subjected to Boc-deprotection
as described in Example 2, Part E to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-9-methoxy-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (6 mg, 0.015 mmol, 8% yield) as a yellow solid. LC/MS (ESI) m/e 370.2[(M+H)
+, calcd for C
21H
28N
3O
1 370.2]; LC/MS retention time (method C):
tR = 2.03min. HPLC retention time (method A): t
R = 7.31 min and HPLC retention time (method B): t
R = 8.32 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.63 (d,
J=6.3 Hz, 1H), 8.50 (d,
J=6.3 Hz, 1H), 8.01 (s, 1H), 7.22 (s, 1H), 4.49 (dd,
J=10.7, 3.1 Hz, 1H), 4.35 (dd,
J=10.9, 6.4 Hz, 1H), 4.09 (s, 3H), 3.83 (s, 3H), 3.81 - 3.75 (m, 1H), 3.19 (s, 3H),
1.92 - 1.74 (m, 2H), 1.73 - 1.61 (m, 1H), 1.07 (d,
J=4.0 Hz, 3H), 1.06 (d,
J=4.0 Hz, 3H).
Example 90
(S)-8-((2-amino-4-methylpentyl)oxy)-9-(difluoromethoxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0521]

Part A: 8-chloro-9-(difluoromethoxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0522] To the stirred solution of 8-chloro-9-hydroxy-4,6-dimethylbenzo[
c][2,7]naphthyridin-5
(6H)-one (0.5 g, 1.456 mmol), prepared as described in Example 89, Part B in acetonitrile
(5 mL) was added K
2CO
3 (0.604 g, 4.37 mmol) followed by sodium 2-chloro-2,2-difluoroacetate (0.444 g, 2.91
mmol). The mixture was heated to 80°C for 18 h. After cooling, the reaction mixture
was diluted with water (50 mL) and extracted with ethyl acetate (2x80 mL). The organic
layer was washed with brine solution, dried over Na
2SO
4, filtered and concentrated under reduced pressure to afford 8-chloro-9-(difluoromethoxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (50 mg, 0.154 mmol, 11% crude yield) as a semi solid. The material was carried
on without further purification. LC/MS (ESI) m/e 325.0 [(M+H)
+, calcd for C
15H
12ClF
2N
2O
2 325.04]; LC/MS retention time (method C):
tR = 2.39 min.

Part B: (S)-tert-butyl (1-((9-(difluoromethoxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0523] 8-Chloro-9-(difluoromethoxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one was subjected to ether synthesis as described in Example 16, Part H to afford
(S)-tert-butyl (1-((9-(difluoromethoxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.2 g, 0.033 mmol, 27%
yield) as a colorless oil. LC/MS (ESI) m/e 506.3 [(M+H)
+, calcd for C
26H
34F
2N
3O
5 506.2]; LC/MS retention time (method E):
tR = 1.21 min.

Part C: (S)-8-((2-amino-4-methylpentyl)oxy)-9-(difluoromethoxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0524] (S)-
tert-Butyl (1-((9-(difluoromethoxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate was subjected to Boc deprotection
as described in Example 2, Part E to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-9-(difluoromethoxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5
(6H)-one (2 mg, 4.24 umol, 13% yield) as a green gum. LC/MS (ESI) m/e 406.2 [(M+H)
+, calcd for C
21H
26F
2N
3O
3, 406.2]; LC/MS retention time (method C):
tR = 1.75 min. HPLC retention time (method B): t
R = 10.11 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.3 (s, 1 H), 8.2 (m, 1 H), 7.25 (s, 1 H), 6.9 (t, 1 H), 4.55 (m, 1 H), 4.45
(m, 1 H), 3.8 (m, 4 H), 3.05-3.2 (m, 3 H), 1.8-1.95 (m, 3 H), 1.05-1.1 (m, 6 H).
Example 91 and Example 92
(S)-8-(2-amino-4,4,4-trifluorobutoxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one and (R)-8-(2-amino-4,4,4-trifluorobutoxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0525]

Part A. Prepared as per literature reference: Ling, F. et.al., J.Org. Chem., 2003, 68, 7544 - 7547.
[0526]

Part B. tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4,4,4-trifluorobutan-2-yl)carbamate
[0527] 8-Chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one and
tert-butyl (4,4,4-trifluoro-1-hydroxybutan-2-yl)carbamate were used for ether synthesis
as described in Example 16, Part H to afford
tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4,4,4-trifluorobutan-2-yl)carbamate (0.22 g, 0.473 mmol,
49% yield) as a semi-solid. LC/MS (ESI) m/e 466.2 [(M+H)
+, calcd for C
23H
27F
3N
3O
4 466.2]; LC/MS retention time (method D):
tR = 0.82 min.

Part C. 8-(2-amino-4,4,4-trifluorobutoxy)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0528] Prepared as described in Example 2, Part E to afford racemic 8-(2-amino-4,4,4-trifluorobutoxy)-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (40 mg, 0.066 mmol, 26% yield, 98% purity) as an off-white solid. The racemic
product was resolved by Chiral preparative SFC purification Conditions: (CHIRALPAK
IA (250x21 mm) 5 micron Mob. Phase: 60% CO
2, Co-solvent: 40% (0.5% DEA in Methanol), Flow rate: 60 g per min, Back pressure:
100 bar) to afford two enantiomers. The absolute stereochemistry of the enantiomers
was not determined.
Enantiomer 1: (7 mg, 0.014 mmol, 6% yield, 98% purity) as an off-white solid. LC/MS (ESI) m/e 366.1
[(M+H)
+, calcd for C
18H
19F
3N
3O
2 366.1]; LC/MS retention time (Method A):
tR = 1.81 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.57 (d,
J=5
.5 Hz, 1H), 8.41 (d,
J=9.0 Hz, 1H), 8.16 (d,
J=6.0 Hz, 1H), 7.12 - 7.05 (m, 2H), 4.30 - 4.08 (m, 2H), 3.77 (s, 3H), 3.62 - 3.58
(m, 1H), 3.10 (s, 3H), 2.74 - 2.58 (m, 1H), 2.44 (m, 1H). Chiral HPLC retention time
(method B):
tR = 8.08 min; Chiral SFC Method (CHIRALPAK IA (250x4.6 mm) 5 micron Mob. Phase: 65%
CO
2, Flow rate: 2.6 g per min, Co-solvent: 35% (0.3% DEA in Methanol), Flow rate: 1.4
g per min, Back pressure: 100 bar)
tR = 3.53 min.
Enantiomer 2: (7 mg, 0.014 mmol, 6% yield, 98% purity) as an off-white solid. LC/MS (ESI) m/e 366.1
[(M+H)
+, calcd for C
18H
19F
3N
3O
2 366.1]; LC/MS retention time (Method A):
tR = 1.81 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.57 (d,
J=5.5 Hz, 1H), 8.41 (d,
J=9.0 Hz, 1H), 8.16 (d,
J=6.0 Hz, 1H), 7.12 - 7.05 (m, 2H), 4.30 - 4.08 (m, 2H), 3.77 (s, 3H), 3.62 - 3.58
(m, 1H), 3.10 (s, 3H), 2.74 - 2.58 (m, 1H), 2.44 (m, 1H). Chiral HPLC retention time
(method B):
tR = 7.93 min. Chiral SFC Method (CHIRALPAK IA (250x4.6 mm) 5 micron Mob. Phase: 65%
CO
2, Flow rate: 2.6 g per min, Co-solvent: 35% (0.3% DEA in Methanol), Flow rate: 1.4
g per min, Back pressure: 100 bar)
tR = 4.62 min.
Example 93
8-(2-amino-4,4,4-trifluorobutoxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0529]

Part A. Prepared as per literature reference: Ling, F. et.al., J.Org. Chem., 2003, 68, 7544 - 7547.
[0530]

Part B. tert-butyl 4,4,4-trifluoro-1-(6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)butan-2-ylcarbamate
[0531] Prepared as described in Example 16, Part H to afford
tert-butyl 4,4,4-trifluoro-1-(6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)butan-2-ylcarbamate (200 mg, 0.221 mmol, 45% yield) as
an off white solid. LC/MS (ESI) m/e 452.2 [(M+H)
+, calcd for C
22H
25F
3N
3O
4 452.2]; LC/MS retention time (Method C):
tR = 2.01min.

Part C. 8-(2-amino-4,4,4-trifluorobutoxy)-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0532] Prepared as described in Example 2, Part E to afford 8-(2-amino-4,4,4-trifluorobutoxy)-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (35 mg, 0.098 mmol, 44% yield) as an off white solid. LC/MS (ESI) m/e 352.0
[(M+H)
+, calcd for C
17H
17F
3N
3O
2 352.1]; LC/MS retention time (Method C):
tR = 1.92 min; HPLC retention time (method A): t
R = 7.07 min; HPLC retention time (method B): t
R = 7.44 min;
1H NMR (400MHz, METHANOL-
d4) δ 9.46 (s, 1H), 8.76 (d,
J=6.0 Hz, 1H), 8.40 (d,
J=8.8 Hz, 1H), 8.23 (d,
J=5.6 Hz, 1H), 7.14 (d,
J=2.4 Hz, 1H), 7.10 (dd,
J=8.8, 2.4 Hz, 1H), 4.22 - 4.13 (m, 2H), 3.79 (s, 3H), 3.67 - 3.57 (m, 1H), 2.71 -
2.63 (m, 1H), 2.49 - 2.40 (m, 1H).
Example 94
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carboxamide
[0533]

[0534] In a 25 mL round-bottomed flask,
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carbonitrile (0.1 g, 0.274 mmol), (prepared as described in
Example 64) and CS
2CO
3 (0.358 g, 1.098 mmol) were taken up in DMF (2 mL) and water (0.6 mL). The mixture
was irradiated in a microwave at 120 °C for 2 h. The reaction mixture was concentrated
under reduced pressure, and diluted with ethyl acetate and water. The combined organics
were concentrated under reduced pressure. The resiude was purified by Prep. HPLC (Column:
Xbridge Phenyl (150 x 4.6 mm) 3.5 micron SC/749 using buffer: 0.05% TFA in water)
to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carboxamide (5 mg, 0.012 mmol, 5% yield) as an off-white solid.
LC/MS (ESI) m/e 383.2 [(M+H)
+, calcd for C
21H
27N
4O
3 383.2]; LC/MS retention time (method C):
tR = 1.74 min; HPLC retention time (method A): t
R = 10.51 min; HPLC retention time (method B): t
R = 10.58 min;
1H NMR (400 MHz, methanol-
d4): δ ppm 8.64 (s, 1H), 8.46 (d, 1H), 8.12 (d, 1H), 6.67 (s, 1H), 3.72-3.79 (m, 1H),
3.69 (s, 3H), 3.65-3.69 (m, 2H), 3.04 (s, 3H), 1.84-1.88 (m, 1H), 1.62-1.68 (m, 1H),
1.49-1.57 (m, 1H), 1.31 (d, 3H), 1.29 (d, 3H).
Example 95
(S)-4,6-dimethyl-8-(4-methyl-2-(methylamino)pentyloxy)benzo[c][2,7]naphthyridin-5(6H)-one
[0535]

Part A: (S)-tert-butyl 1-(4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-yl(methyl)carbamate
[0536] (
S)-
tert-Butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.150 g, 0.341 mmol),
prepared as described in Example 16, Part H, was taken up in DMF (1 mL) and cooled
to 0 °C. NaH (0.027 g, 0.683 mmol) was added and the reaction mixture was stirred
for 45 min at °0 C. Iodomethane (0.107 mL, 1.706 mmol) was then added and reaction
mixture was warmed to room temperature and stirred for 15 min. The mixture was quenched
with ice and partitioned between ethyl acetate (4 mL) and water (2 mL). The organic
layer was separated, washed with brine (2 mL), dried over sodium sulfate, filtered
and concentrated under reduced pressure to afford crude which was purified by preparative
HPLC to afford
(S)-
tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)(methyl)carbamate (60 mg, 0.125 mmol,
37% yield) as a light yellow solid. LC/MS (ESI) m/e 454.4 [(M+H)
+, calcd for C
26H
16N
3O
2 454.3]; LC/MS retention time (method E):
tR = 1.21 min.

Part B: (S)-4,6-dimethyl-8-(4-methyl-2-(methylamino)pentyloxy)benzo[c][2,7]naphthyridin-5(6H)-one
[0537] Prepared as described in Example 2, Part E to afford title compound (30 mg, 0.070
mmol, 64% yield) as a pale yellow solid. LC/MS (ESI) m/e 354.0 [(M+H)
+, calcd for C
21H
28N
3O
2 354.2] LC/MS retention time (method C):
tR = 1.81 min. HPLC retention time (method A): t
R = 8.22 min and HPLC retention time (method B): t
R = 9.21 min.
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.74 (d,
J=7.0 Hz, 1H), 8.69 - 8.65 (m, 1H), 8.62 (d,
J=9.0 Hz, 1H), 7.30 - 7.22 (m, 2H), 4.62 (dd,
J=11.0, 3.0 Hz, 1H), 4.49 (dd,
J=11.5, 5.0 Hz, 1H), 3.85 (s, 3H), 3.74 (dd,
J=8.3, 3.8 Hz, 1H), 3.28 (s, 3H), 2.84 (s, 3H), 1.99 - 1.78 (m, 2H), 1.76 - 1.63 (m,
1H), 1.07 (d,
J=6.0 Hz, 6H).
Example 96
(S)-8-((2-amino-4-methylpentyl)oxy)-N,N,4,6-tetramethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carboxamide
[0538]

Part A: (S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carboxylic acid
[0539] To a solution of
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carbonitrile (450 mg, 1.235 mmol), prepared as described in
Example 64, in ethanol (5 mL) and water (5 mL) was added NaOH (494 mg, 12.35 mmol).
The mixture was heated to 80 °C for 12 h. The volatiles were evaporated and the residue
was diluted with water The pH was adjusted to 3 using 1.5N HCl. The solution was extracted
with ethyl acetate (2 x 5 mL). The combined organic layers were dried over sodium
sulfate, filtered and concentrated under reduced pressure to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carboxylic acid (90 mg, 0.235 mmol, 19% crude yield) as a yellow
solid. The material was carried forward without further purification. LC/MS (ESI)
m/e 384.1 [(M+H)
+, calcd for C
21H
26N
3O
4 384.2]; LC/MS retention time (method D):
tR = 0.72 min.

Part B: (S)-8-((2-amino-4-methylpentyl)oxy)-N,N,4,6-tetramethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carboxamide
[0540] The solution of
(S)-8-((2-amino-4-methylpentyl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carboxylic acid (90 mg, 0.070 mmol) in DMF (0.9 mL) was cooled
to 0 °C. HOBT (21.57 mg, 0.141 mmol) and EDC (20.25 mg, 0.106 mmol) were added and
stirred for 5 min. To this dimethylamine (0.282 mL, 0.563 mmol) was added followed
by DIPEA (0.037 mL, 0.211 mmol) and stirred for 30 min. The reaction was then warmed
to rt and stirred for 12 h. The reaction was quenched by addition of ice, the solid
crashed out was filtered. The solid was washed with excess of water and dried completely
to afford the orange oil upon warming to rt. The crude product was purified by prep
HPLC (0.1% TFA in ACN : Water) to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-
N,
N,4,6-tetramethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridine-9-carboxamide, 2 TFA (3.36 mg, 4.95 µmol, 7 % yield) as a light
green solid. LC/MS (ESI) m/e 411.2 [(M+H)
+, calcd for C
23H
31N
4O, 411.2] LC/MS retention time (method C):
tR = 2.22 min. HPLC retention time (method A): t
R = 10.98 min and HPLC retention time (method B): t
R = 11.63
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.44 (d,
J=6.0 Hz, 1H), 8.31 (d,
J=6.0 Hz, 1H), 8.25 (s, 1H), 6.76 (s, 1H), 3.76 (s, 3H), 3.69 (dd,
J=4.8, 3.3 Hz, 2H), 3.34 (s, 3H), 3.20 - 3.08 (m, 7H), 1.84 - 1.78 (m, 1H), 1.66 -
1.51 (m, 2H), 1.05 (d,
J=7.0 Hz, 3H), 0.99 (d,
J=6.5 Hz, 3H).
Example 97
8-(2-amino-2,4-dimethylpentyloxy)-1-fluoro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0541]

Part A: tert-butyl 1-(1-fluoro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-2,4-dimethylpentan-2-ylcarbamate
[0542] Prepared as described in Example 16, Part H from 8-chloro-1-fluoro-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one, prepared as described in Example 85, Part E, to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-7-fluoro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (35 mg, 0.076 mmol, 50 % yield). LC/MS (ESI) m/e 458.2 [(M+H)
+, calcd for C
25H
33FN
3O
4 458.2]; LC/MS retention time (method C):
tR = 2.15 min.

Part B: 8-(2-amino-2,4-dimethylpentyloxy)-1-fluoro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0543] Prepared as described in Example 2, Part E to afford 8-(2-amino-2,4-dimethylpentyloxy)-1-fluoro-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (16.5 mg, 0.035mmol, 45 % yield as a white solid. LC/MS (ESI) m/e 358.2[(M+H)
+, calcd for C
20H
25FN
3O
2 358.2]; LC/MS retention time (method C):
tR = 2.06 min; HPLC retention time (method A): t
R = 11.79 min; HPLC retention time (method B): t
R = 6.66 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 9.41 (s, 1H), 8.79 (d,
J=4.8 Hz, 1H), 8.71 (dd,
J=9.2, 2.9 Hz, 1H), 7.24 (d,
J=2.3 Hz, 1H), 7.22 - 7.15 (m, 1H), 4.36 (d,
J=10.3 Hz, 1H), 4.24 (d,
J=10.3 Hz, 1H), 3.84 (s, 3H), 2.02 - 1.83 (m, 2H), 1.80 - 1.70 (m, 1H), 1.55 (s, 3H),
1.11 (d,
J=6.5 Hz, 3H), 1.06 (d,
J=6.3 Hz, 3H).
Example 98
(S)-8-((2-amino-4-methylpentyl)oxy)-1-methoxy-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0544]

Part A: 8-chloro-1-methoxy-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0545] To the solution of 8-chloro-1-fluoro-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (40 mg, 0.152 mmol), prepared as described in Example 85, Part E, in MeOH (0.2
mL) in a microwave vial, 18-crown-6 (4.03 mg, 0.015 mmol) and sodium methoxide (32.9
mg, 0.152 mmol) in methanol were added and heated in a microwave oven at 100 °C for
30 min. Upon completion, the reaction mixture was diluted with water and extracted
with ethyl acetate (2 x 5mL). The combined organic layers were washed with brine solution,
dried over sodium sulfate, filtered and concentrated under reduced pressure to afford
8-chloro-1-methoxy-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (40 mg, 0.146 mmol, 96 % crude yield) as a white solid. The material was carried
forward without further purification. LC/MS (ESI) m/e 275.0 [(M+H)
+, calcd for C
14H
12ClN
2O
2 275.05]; LC/MS retention time (method D):
tR = 0.72 min.

Part B: (S)-tert-butyl (1-((1-methoxy-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0546] To the solution of 8-chloro-1-methoxy-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (40 mg, 0.146 mmol) in toluene (0.5 mL) was added cesium carbonate (71.2 mg,
0.218 mmol) and di-
tert-butyl(2',4',6'-triisopropyl-[1,1'-biphenyl]-2-yl)phosphine (6.18 mg, 0.015 mmol).
The solution was purged with N2 for 5 min. To this palladium (II) acetate (1.635 mg,
7.28 µmol) was added and the solution purged with N2 for 10 min. The resultant mixture
was heated at 90 °C for 21 h. After cooling, the reaction mixture was filtered through
diatomaceous earth (Celite
®), eluting with EtOAc. The filtrate was concentrated under reduced pressure. The crude
product was purified by silica gel chromatography using hexanes and ethyl acetate
to afford
(S)-
tert-butyl (1-((1-methoxy-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (40 mg, 0.041 mmol, 28
% yield). LC/MS (ESI) m/e 456.2 [(M+H)
+, calcd for C
25H
34N
3O
5 456.2]; LC/MS retention time (method D):
tR = 0.9 min.

Part C: (S)-8-((2-amino-4-methylpentyl)oxy)-1-methoxy-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0547] To the solution of
(S)-
tert-butyl (1-((1-methoxy-6-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (40 mg, 0.041 mmol) in
DCM (0.9 mL) cooled to 0 °C, TFA (0.2 mL, 2.60 mmol) was added dropwise and stirred
for 5 min. The reaction mixture was warmed to rt and stirred for 3 h. The volatiles
were removed under reduced pressure. The crude product was purified by prep HPLC using
(0.1% TFA in ACN:water) to afford
(S)-8-((2-amino-4-methylpentyl)oxy)-1-methoxy-6-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one, 2 TFA (17.11mg, 0.028 mmol, 69 % yield) as white solid. LC/MS (ESI) m/e 356.0
[(M+H)
+, calcd for C
20H
26N
3O
3 356.2]; LC/MS retention time (method C):
tR = 1.82 min; HPLC retention time (method A):
tR = 9.44 min; HPLC retention time (method B): t
R = 9.78 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 9.17 (s, 1H), 9.14 (d,
J=9.0 Hz, 1H), 8.54 (s, 1H), 7.09 (d,
J=2.5 Hz, 1H), 7.02 (dd,
J=9.0, 2.5 Hz, 1H), 4.21 (s, 3H), 4.19 - 4.15 (m, 1H), 4.04 - 3.95 (m, 2H), 3.78 (s,
3H), 1.97 - 1.80 (m, 1H), 1.51 - 1.42 (m, 2H), 1.04 (d,
J=6.5 Hz, 3H), 1.02 (d,
J=6.5 Hz, 3H).
Example 99
(S)-8-(2-amino-4-methylpentyloxy)-7-methoxy-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0548]

Part A. 3-bromo-6-chloro-2-fluorophenol
[0549] To a stirred solution of 1-bromo-4-chloro-2-fluorobenzene (5 g, 23.87 mmol) in tetrahydrofuran
(40 mL) cooled to -78 °C was added LDA (14.92 mL, 29.8 mmol) dropwise. The reaction
mixture was stirred at this temperature for 30 min. then allowed to warm to -20 °C
and stirred for 30 min. The reaction was then cooled to - 78 °C and trimethyl borate
(3.47 mL, 31.0 mmol) dissolved in THF (5 mL) was added dropwise. The reaction mixture
was warmed to -20°C and stirred for 1 h. The reaction mixture was then cooled to -78
°C and peracetic acid (16 mL, 84 mmol) as slowly added dropwise. The mixture was allowed
to warm to rt and stirred for 12 h. The reaction mixture was again cooled to 0 °C
and quenched with 5% ammonium chloride The solution was extracted with ethyl acetate
(2x50 mL). The combined organic layers were washed with brine (50 mL), dried over
sodium sulfate, filtered and concentrated under reduced pressure to afford 3-bromo-6-chloro-2-fluorophenol
(4.99 g, 18.25 mmol, 76 % crude yield) as a yellow oil. The material was carried forward
without further purification.LC/MS (ESI) m/e 225.1 [(M+H)
+, calcd for C
6H
4BrClFO 224.9]; LC/MS retention time (method E):
tR = 0.87 min.

Part B. 1-bromo-4-chloro-2-fluoro-3-methoxybenzene
[0550] To a stirred solution of 3-bromo-6-chloro-2-fluorophenol (4.2 g, 18.63 mmol) in acetonitrile
(35 mL) was added potassium carbonate (5.15 g, 37.3 mmol) followed by methyl iodide
(2.330 mL, 37.3 mmol) dropwise at rt. The reaction mixture was heated to 85 °C for
3 h. After cooling, the volatiles were concentrated under reduced pressure and the
residue was diluted with water (50 mL) and extracted with ethyl acetate (2x80 mL).
The combined organic layers were washed with brine (100 mL), dried over sodium sulfate,
filtered and concentrated under reduced pressure to afford 1-bromo-4-chloro-2-fluoro-3-methoxybenzene
(4 g, 16.7 mmol, 90% crude yield) as a brown solid. The material was carried forward
without further purification.
1H NMR (400MHz,
CDCl3) δ ppm 7.2 (m, 1 H), 7.04 (m, 1 H), 3.98 (s, 3 H).

Part C. 2-(4-chloro-2-fluoro-3-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
[0551] To a stirred solution of 1-bromo-4-chloro-2-fluoro-3-methoxybenzene (3 g, 12.53 mmol)
in tetrahydrofuran (20 mL) cooled to -10 °C was added isopropylmagnesium bromide (5.18
mL, 15.03 mmol) dropwise and the reaction mixture was stirred at -10 °C for 1 h. The
reaction mixture was then warmed to 0 °C and stirred for 1 h. The reaction was then
cooled to -10 °C and 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.56 mL,
12.53 mmol) was slowly added dropwise. The reaction mixture was allowed to warm to
room temperature and stirred for 16 h. The reaction mixture was quenched with 5% aqueous
sodium hydroxide and extracted with ethyl acetate (2x25 mL). The combined organic
layers were washed with brine solution, dried over sodium sulfate, filtered and concentrated
under reduced pressure to afford 2-(4-chloro-2-fluoro-3-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
(2.3 g, 8.03 mmol, 64% crude yield) as a brown oil. The material was carried forward
without further purification.
1H NMR (400MHz,
CDCl3) δ ppm 7.35 (m, 1 H), 7.15 (m, 1 H), 3.95 (s, 3 H), 1.33 (s, 6 H), 1.23 (s, 6 H).

Part D. methyl 4-(4-chloro-2-fluoro-3-methoxyphenyl)-2-methylnicotinate
[0552] A mixture of methyl 4-chloro-2-methylnicotinate (1.5 g, 8.08 mmol), 2-(4-chloro-2-fluoro-3-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
(2.316 g, 8.08 mmol), phosphoric acid, potassium salt (3.43 g, 16.16 mmol) and PdCl
2(dppf)-CH
2Cl
2 adduct (0.660 g, 0.808 mmol) in 1,4-dioxane (25 mL) and water (5 mL) was purged with
nitrogen for 5 min. The reaction was then heated to 100 °C for 18 h. After cooling,
the reaction was diluted with water (50 mL) and extracted with ethyl acetate (2x75
mL). The combined organic layers were washed with brine solution, dried over sodium
sulfate, filtered and concentrated. The residue was purified by silica gel chromatography
using 50% ethyl acetate in hexanes to yield methyl 4-(4-chloro-2-fluoro-3-methoxyphenyl)-2-methylnicotinate
(1.2 g, 2.52 mmol, 31% yield) as pale brown oil. LC/MS (ESI) m/e 309.9 [(M+H)
+, calcd for C
15H
14ClFNO
3 310.1]; LC/MS retention time (method D):
tR = 0.84 min.

Part E. 4-(4-chloro-2-fluoro-3-methoxyphenyl)-2-methylnicotinic acid
[0553] Prepared as described in Example 16, Part E by hydrolysis of the methyl 4-(4-chloro-2-fluoro-3-methoxyphenyl)-2-methylnicotinate
to afford 4-(4-chloro-2-fluoro-3-methoxyphenyl)-2-methylnicotinic acid (780 mg, 2.137
mmol, 93 % yield) as a brown oil. LC/MS (ESI) m/e 295.9 [(M+H)
+, calcd for C
14H
12ClFNO
3 296.04]; LC/MS retention time (method D):
tR = 0.61 min.

Part F. 4-(4-chloro-2-fluoro-3-methoxyphenyl)-N-(4-methoxybenzyl)-2-methylnicotinamide
[0554] To a stirred solution of (4-methoxyphenyl)methanamine (0.437 g, 3.18 mmol) in CH
2Cl
2 (25 mL) was added DIEA (0.556 mL, 3.18 mmol) and the reaction mixture was stirred
at 0 °C for 15 min. 4-(4-chloro-2-fluoro-3-methoxyphenyl)-2-methylnicotinoyl chloride
(1 g, 3.18 mmol) (prepared by treatment of carboxylic acid with thionyl chloride)
dissolved in 10 mL of DCM was then added to the reaction mixture and the reaction
was stirred at rt for 10 h. The reaction was quenched by addition of water (50 mL)
and the solution was extracted with DCM (2x50 mL). The combined organic layers were
washed with brine solution 50 mL, dried over sodium sulfate, filtered and concentrated
under reduced pressure. The residue was purified by silica gel chromatography using
ethyl acetate in hexanes as eluant to yield 4-(4-chloro-2-fluoro-3-methoxyphenyl)-N-(4-methoxybenzyl)-2-methylnicotinamide
(800 mg, 1.109 mmol, 35% yield) as a brown oil. LC/MS (ESI) m/e 415.1 [(M+H)
+, calcd for C
22H
21ClFN
2O
3 415.1]; LC/MS retention time (method D):
tR = 0.78 min.

Part G. 8-chloro-7-methoxy-6-(4-methoxybenzyl)-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0555] Prepared as described in Example 2, Part C from 4-(4-chloro-2-fluoro-3-methoxyphenyl)-N-(4-methoxybenzyl)-2-methylnicotinamide
to afford 8-chloro-7-methoxy-6-(4-methoxybenzyl)-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (110 mg, 0.245 mmol, 34% yield) as yellow solid. LC/MS (ESI) m/e 395.1 [(M+H)
+, calcd for C
22H
20ClN
2O, 395.1] LC/MS retention time (method D):
tR = 0.81 min.

Part H. (S)-tert-butyl 1-(7-methoxy-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0556] Prepared as described in Example 16, Part H to afford the title compound (325 mg,
0.119 mmol, 49% crude yield) as a white solid. The material was carried forward without
purification. LC/MS (ESI) m/e 576.3 [(M+H)
+, calcd for C
33H
42N
3O
6 576.3]; LC/MS retention time (method D):
tR = 0.99 min.

Part I. (S)-8-(2-amino-4-methylpentyloxy)-7-methoxy-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0557] Prepared as described in Example 2, Part E to afford
(S)-8-(2-amino-4-methylpentyloxy)-7-methoxy-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (12.3 mg, 0.033 mmol, 28% yield) as a white solid. LC/MS (ESI) m/e 356.2 [(M+H)
+, calcd for C
20H
26N
3O
3 356.2]; LC/MS retention time (method C):
tR = 1.49 min; HPLC retention time (method A): t
R = 7.36 min; HPLC retention time (method B): t
R = 8.52 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.59 (d,
J=5.5 Hz, 1H), 8.14 (d,
J=5.5 Hz, 1H), 8.10 (d,
J=9.0 Hz, 1H), 7.11 (d,
J=9.0 Hz, 1H), 4.18 (dd,
J=9.3, 4.3 Hz, 1H), 4.08 - 4.03 (m, 1H), 4.02 (s, 3H), 4.01 - 3.96 (m, 1H), 3.10 (s,
3H), 1.91 - 1.80 (m, 1H), 1.57 - 1.40 (m, 2H), 1.03 (d,
J=6.5 Hz, 3H), 1.01 (d,
J=7.0 Hz, 3H).
Example 100
(S)-8-(2-amino-4-methylpentyloxy)-9-bromo-7-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0558]

Part A: (S)-tert-butyl 1-(9-bromo-7-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0559] Prepared from
(S)-
tert-butyll-(7-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate prepared as described in
Example 82, Part C, using the method described in Example 3, Part A to afford title
compound (120 mg, 0.065 mmol, 44% yield). LC/MS (ESI) m/e 642.4 [(M+H)
+, calcd for C
32H
38BrFN
3O
5 642.2]; LC/MS retention time (method E):
tR = 1.26 min.

Part B: (S)-8-(2-amino-4-methylpentyloxy)-9-bromo-7-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0560] Prepared as described in Example 2, Part E to afford (
S)-8-(2-amino-4-methylpentyloxy)-9-bromo-7-fluoro-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (3.5 mg, 8.22 µmol, 13 % yield) as an off-white solid. LC/MS (ESI) m/e 423.0
[(M+H)
+, calcd for C
19H
22BrFN
3O
2 423.3]; LC/MS retention time (method C):
tR = 2.10 min; HPLC retention time (method A): t
R = 8.58 min; HPLC retention time (method B): t
R = 9.08 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.73 (d,
J=6.0 Hz, 1H), 8.57 (d,
J=2.0 Hz, 1H), 8.40 (d,
J=6.0 Hz, 1H), 4.51 (dd,
J=10.3, 2.5 Hz, 1H), 4.38 (dd,
J=10.4, 5.6 Hz, 1H), 3.78 - 3.73 (m, 1H), 3.17 (s, 3H), 1.94 - 1.82 (m, 2H), 1.73 -
1.60 (m, 1H), 1.08 (d,
J=2.5 Hz, 3H), 1.06 (d,
J=2.8 Hz, 3H).
Example 101
(S)-8-(2-amino-4-methylpentyloxy)-9-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0561]

Part A: 4-(4-chloro-2,5-difluorophenyl)-N-(4-methoxybenzyl)-2-methylnicotinamide
[0562] Prepared as described in Example 82, Part A from 4-(4-chloro-2,5-difluorophenyl)-2-methylnicotinic
acid (prepared as described in Example 70, Part D) to afford title compound (440 mg,
1.015 mmol, 87 % yield) as an off-white solid. LC/MS (ESI) m/e 403.1 [(M+H)
+, calcd for C
21H
18ClF
2N
2O
2 403.1]; LC/MS retention time (method E):
tR = 0.93 min.

Part B: 8-chloro-9-fluoro-6-(4-methoxybenzyl)-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0563] Prepared as described in Example 73, Part B to afford 8-chloro-9-fluoro-6-(4-methoxybenzyl)-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (260mg, 0.669 mmol, 61 % yield) as a white solid. LC/MS (ESI) m/e 383.0 [(M+H)
+, calcd for C
21H
17ClFN
2O
2 383.1]; LC/MS retention time (method C):
tR = 2.04 min.

Part C: (S)-tert-butyl 1-(9-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0564] Prepared as described in Example 16, Part H to afford
(S)-
tert-butyl 1-(9-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate (0.2 g, 0.244 mmol, 62% yield).
LC/MS (ESI) m/e 564.4 [(M+H)
+, calcd for C
32H
39FN
3O
5 564.3]; LC/MS retention time (method E):
tR = 1.25 min.

Part D: (S)-8-(2-amino-4-methylpentyloxy)-9-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0565] Prepared as described in Example 2, Part E to afford title compound (55 mg, 0.158
mmol, 87 % yield) as a white solid. LC/MS (ESI) m/e 344.0 [(M+H)
+, calcd for C
19H
23FN
3O
2 344.2]; LC/MS retention time (method C):
tR = 1.76 min; HPLC retention time (method A): t
R = 7.88 min; HPLC retention time (method B): t
R = 7.92 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.60 (d,
J=5.8 Hz, 1H), 8.15 (d,
J=12.0 Hz, 1H), 8.08 (d,
J=5.8 Hz, 1H), 6.99 (d,
J=7.5 Hz, 1H), 4.22 - 4.12 (m, 1H), 4.06 - 3.92 (m, 1H), 3.40 (br. s., 1H), 3.10 (s,
3H), 1.92 - 1.80 (m, 1H), 1.59 - 1.41 (m, 2H), 1.03 (d,
J=6.5 Hz, 3H), 1.01 (d,
J=6.5 Hz, 3H).
Example 102
8-(2-amino-2,4-dimethylpentyloxy)-9-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0566]

Part A. tert-butyl 1-(9-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-2,4-dimethylpentan-2-ylcarbamate
[0567] Prepared from coupling of 8-chloro-9-fluoro-6-(4-methoxybenzyl)-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (synthesis described in Example 101, Part C) following the procedure described
in Example 16, Part H to afford title compound (0.130 g, 0.123 mmol, 47% yield) as
a brown oil. LC/MS (ESI) m/e 578.5 [(M+H)
+, calcd for C
33H
41FN
3O
5 578.3]; LC/MS retention time (method E):
tR = 1.28 min.

Part B. 8-(2-amino-2,4-dimethylpentyloxy)-9-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0568] Prepared as described in Example 2, Part E to afford title compound (10 mg, 0.017
mmol, 22% yield) as a pale yellow solid. LC/MS (ESI) m/e 358.0 [(M+H)
+, calcd for C
20H
25FN
3O
2 358.2]; LC/MS retention time (method C):
tR = 1.69 min; HPLC retention time (method A): t
R = 7.87 min; HPLC retention time (method B): t
R = 8.59 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.67 (d,
J=6.3 Hz, 1H), 8.39 (d,
J=6.3 Hz, 1H), 8.32 (d,
J=12.0 Hz, 1H), 7.08 (d,
J=7.3 Hz, 1H), 4.44 - 4.15 (m, 2H), 3.37 - 3.35 (m, 1H), 3.19 (s, 3H), 1.97 - 1.83
(m, 2H), 1.81 - 1.70 (m, 1H), 1.56 (s, 2H), 1.10 (d,
J=6.3 Hz, 3H), 1.06 (d,
J=6.3 Hz, 3H).
Example 103
(S)-8-(2-amino-4-methylpentyloxy)-9-ehloro-7-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0569]

Part A: (S)-tert-butyl 1-(9-chloro-7-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0570] Prepared as described in Example 41, Part A from
(S)-
tert-butyl (1-((7-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (synthesis described in
Example 82, Part C) to afford title compound (2135 mg, 0.063 mmol, 60% crude yield)
as a yellow solid. The material was carried forward without purification. LC/MS (ESI)
m/e 598.3 [(M+H)
+, calcd for C
32H
38ClFN
3O
5 598.2]; LC/MS retention time (method E):
tR = 1.32 min.

Part B. (S)-8-(2-amino-4-methylpentyloxy)-9-chloro-7-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0571] To a solution of
(S)-
tert-butyl (1-((9-chloro-7-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (.08 g, 0.037 mmol) in
TFA (8 mL) cooled to 0 °C was added methanesulfonic acid (0.243 µl, 3.75 µmol). The
reaction mixture was then heated at 70 °C for 2h. The volatiles were evaporated. The
residue was taken up in water and neutralized with 10% aqueous NaHCO3. The solution
was extracted with EtOAc (3x15 mL). The combined organic layers were washed with brine
(1x15 mL), dried over Na2SO4, filtered and concentrated under reduced pressure. The
residue was purified by preparative HPLC (Column:X-Bridge(19X150mm) 5µm, Flow rate:15ml/min;
Solvent A:0.01% TFA, Solvent B:ACN) to affored
(S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-7-fluoro-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one, 3 TFA (9.5mg, 0.013 mmol, 34.4 % yield) as an off-white solid. LC/MS (ESI)
m/e 378.0 [(M+H)
+, calcd for C
19H
22ClFN
3O
2 378.1]; LC/MS retention time (method C):
tR = 2.02 min; HPLC retention time (method A): t
R = 7.47 min; HPLC retention time (method B): t
R = 8.41 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.70 (d,
J=6.0 Hz, 1H), 8.40 (d,
J=2.0 Hz, 1H), 8.35 (d,
J=6.3 Hz, 1H), 4.49 (dd,
J=10.7, 2.6 Hz, 1H), 4.35 (dd,
J=10.5, 5.8 Hz, 1H), 3.75 - 3.69 (m, 1H), 3.14 (s, 3H), 1.90 - 1.74 (m, 2H), 1.70 -
1.56 (m, 1H), 1.04 (d,
J=2.3 Hz, 3H), 1.03 (d,
J=2.5 Hz, 3H).
Example 104
(S)-8-(2-amino-4-methylpentyloxy)-9-(methoxymethyl)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0572]

Part A. (S)-tert-butyl 1-(9-(methoxymethyl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-4-methylpentan-2-ylcarbamate
[0573] Prepared as described in Example 16, Part H to afford title compound (S)-
tert-butyl (1-((9-(methoxymethyl)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (100 mg, 0.066 mmol, 84
% yield). LC/MS (ESI) m/e 484.4 [(M+H)
+, calcd for C
27H
38N
3O
5 484.3]; LC/MS retention time (method B):
tR = 1.65 min.

Part B. (S)-8-(2-amino-4-methylpentyloxy)-9-(methoxymethyl)-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0574] Prepared as described in Example 2, Part E to afford title compound (9 mg, 0.022
mmol, 33 % yield) as a yellow solid. LC/MS (ESI) m/e 384.2 [(M+H)
+, calcd for C
22H
30N
3O
3 384.2]; LC/MS retention time (method C):
tR = 1.66 min; HPLC retention time (method A): t
R = 7.96 min; HPLC retention time (method B): t
R = 9.01 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.54 (d,
J=5.9 Hz, 1H), 8.33 (s, 1H), 8.11 (d,
J=5.8 Hz, 1H), 7.00 (s, 1H), 4.73 - 4.55 (m, 2H), 4.33 (dd,
J=10.0, 3.5 Hz, 1H), 4.13 (dd,
J=9.9, 6.8 Hz, 1H), 3.75 (s, 3H), 3.59 - 3.50 (m, 1H), 3.47 (s, 3H), 3.06 (s, 3H),
1.97 - 1.77 (m, 1H), 1.69 - 1.45 (m, 2H), 1.04 (d,
J=4.7 Hz, 3H), 1.02 (d,
J=4.7 Hz, 3H).
Example 105
8-(2-amino-2,4-dimethylpentyloxy)-7-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0575]

Part A. 4-(4-bromo-2,3-difluorophenyl)-N-(4-methoxybenzyl)-2-methylnicotinamide
[0576] Prepared as described in Example 82, Part A to afford 4-(4-bromo-2,3-difluorophenyl)-
N-(4-methoxybenzyl)-2-methylnicotinamide (0.320 g, 0.693 mmol, 97 % yield) as an off-white
solid. LC/MS (ESI) m/e 447.0 [(M+H)
+, calcd for C
21H
18BrF
2N
2O
2 447.0]; LC/MS retention time (method E):
tR = 0.95 min.

Part B. 8-bromo-7-fluoro-6-(4-methoxybenzyl)-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0577] Prepared as described in Example 2, Part C to afford 8-bromo-7-fluoro-6-(4-methoxybenzyl)-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.12 g, 0.269 mmol, 90 % yield) as an off-white solid. LC/MS (ESI) m/e 427.1
[(M+H)
+, calcd for C
21H
17BrFN
2O
2 427.0]; LC/MS retention time (method E):
tR = 1.15 min.

Part C. tert-butyl 1-(7-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yloxy)-2,4-dimethylpentan-2-ylcarbamate
[0578] Prepared as described in Example 16, Part H to afford (R)-
tert-butyl (1-((7-fluoro-6-(4-methoxybenzyl)-4-methyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-2,4-dimethylpentan-2-yl)carbamate (0.025 g, 0.042 mmol,
13 % yield). LC/MS (ESI) m/e 578.5 [(M+H)
+, calcd for C
33H
41FN
3O
5 578.3]; LC/MS retention time (method E):
tR = 1.28 min.

Part D. 8-(2-amino-2,4-dimethylpentyloxy)-7-fluoro-4-methylbenzo[c][2,7]naphthyridin-5(6H)-one
[0579] Prepared as described in Example 17, Part I to afford 8-(2-amino-2,4-dimethylpentyloxy)-7-fluoro-4-methylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.013 g, 0.030 mmol, 69 % yield) as an off-white solid. LC/MS (ESI) m/e 358.0
[(M+H)
+, calcd for C
20H
25FN
3O
2 358.2]; HPLC retention time (method A): t
R = 7.71 min; HPLC retention time (method B): t
R = 8.57 min;
1H NMR (400MHz, METHANOL-
d4) δ ppm 8.75 - 8.70 (m, 1H), 8.70 - 8.63 (m, 1H), 8.36 (dd,
J=9.3, 1.8 Hz, 1H), 7.34 (dd,
J=9.3, 7.8 Hz, 1H), 4.47 - 4.39 (m, 1H), 4.38 - 4.30 (m, 1H), 3.26 (s, 3H), 1.96 -
1.85 (m, 2H), 1.81 - 1.70 (m, 1H), 1.55 (s, 3H), 1.10 (d,
J=6.5 Hz, 3H), 1.06 (d,
J=6.0 Hz, 3H).
Example 106
(S)-8-((2-amino-5,5-difluoropent-4-en-1-yl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c]
[2,7]naphthyridine-9-carbonitrile
[0580]

Part A: (S)-dimethyl 2-((tert-butoxycarbonyl)amino)succinate
[0581] A 0 °C suspension of L-aspartic acid (10.1 g, 76.0 mmol) in anhydrous methanol (100
mL) was treated with trimethylsilyl chloride (24.7 g, 228 mmol) via rapid dropwise
addition. The cooling bath was removed and the resulting solution stirred at ambient
temperature overnight (16 h) and then concentrated under reduced pressure. The resulting
oil was taken up in dichloromethane (100 mL), treated with di-
t-butyl dicarbonate (17.4 g, 80.1 mmol) and diisopropylethylamine (26.5 mL, 152 mmol)
and stirred at ambient temperature overnight (16 h). The resulting solution was washed
with 0.25 N aqueous hydrochloric acid (3x50 mL), 0.25 N aqueous sodium hydroxide (3x50
mL), and brine (1x50 mL); dried over MgSO
4 and concentrated under reduced pressure to afford
(S)-dimethyl 2-((
tert-butoxycarbonyl)amino)succinate (15.9 g, 60.9 mmol, 80% crude yield) as a near colorless
oil. The crude product was used in the next step without further purification.
1H NMR (400MHz,
CDCl3) δ ppm 5.50 (br. s., 1H), 4.60 (br. s., 1H), 3.78 (s, 3H), 3.71 (s, 3H), 3.02 (dd,
J=16.9, 4.4 Hz, 1H), 2.84 (dd,
J=16.8, 4.8 Hz, 1H), 1.47 (s, 9H).

Part B: (S)-dimethyl 2-[bis(tert-butoxycarbonyl)amino]butane-1,4-dioate
[0582] A 0 °C solution of
(S)-dimethyl 2-((
tert-butoxycarbonyl)amino)succinate (15.8 g, 60.5 mmol) in acetonitrile (200 mL) was treated
with di-
t-butyl dicarbonate (13.9 g, 63.5 mmol) and 4-dimethylaminopyridine (1.48 g, 12.1 mmol).
The cooling bath was removed and the reaction solution stirred at ambient temperature
overnight (18 h). The resulting solution was concentrated under reduced pressure.
The residue was dissolved in ethyl acetate (200 mL), washed with 0.25 N aqueous hydrochloric
acid (2x50 mL), 0.25N aqueous sodium hydroxide (2x50 mL), and brine (1x50 mL); dried
over magnesium sulfate and concentrated under reduced pressure to afford
(S)-dimethyl 2-[bis(
tert-butoxycarbonyl)amino]butane-1,4-dioate (18.8 g, 52.0 mmol, 86% crude yield) as a
pale yellow oil. The crude product was used without further purification.
1H NMR (400MHz,
CDCl3) δ ppm 5.46 (t,
J=6.8 Hz, 1H), 3.72 (s, 3H), 3.74 (s, 3H), 3.26 (dd,
J=16.4, 7.2 Hz, 1H), 2.75 (dd,
J=16.3, 6.5 Hz, 1H), 1.52 (s, 18H).

Part C: (S)-methyl-2-{(tert-butoxy)-N-[(tert-butyl)oxycarbonyl]carbonylamino{-4-oxobutanoate
[0583] A -78 °C solution of
(S)-dimethyl 2-[bis(
tert-butoxycarbonyl)amino]butane-1,4-dioate (9.07 g, 25.1 mmol) in diethyl ether (100
mL) was treated dropwise with 1 M diisobutyl aluminum hydride in dichloromethane (37.6
mL, 37.6 mmol). The resulting solution was stirred for 15 min and then quenched sequentially
in 15 minutes intervals with water (3.3 mL), 1N aqueous sodium hydroxide (10 mL),
and again with water (3.3 mL). The resulting suspension was filtered through diatomaceous
earth (Celite
®) and concentrated under reduced pressure to afford (S)-methyl-2-{(
tert-butoxy)-
N-[(
tert-butyl)oxycarbonyl]carbonylamino{-4-oxobutanoate (8.26 g, 24.9 mmol, 99% crude yield)
as a colorless oil. The crude product was used without further purification.
1H NMR (400MHz,
CDCl3) δ ppm 9.81 (s, 1H), 5.55 (t,
J=6.4 Hz, 1H), 3.75, (s, 3H), 3.43 (ddd,
J=18.0, 5.9, 1.0 Hz, 1H), 2.85 (ddd,
J=17.9, 6.0, 1.0 Hz, 1H), 1.52 (s, 18H).

Part D: (S)-methyl 2-((tert-butoxycarbonyl)amino)-4-oxobutanoate
[0584] A solution of
(S)-methyl-2-{(
tert-butoxy)-
N-[(
tert-butyl)oxycarbonyl]carbonylamino{-4-oxobutanoate (29.2 g, 88.0 mmol) in acetonitrile
(300 mL) was treated with lithium bromide (11.5 g, 132 mmol), heated to reflux for
2 h, and then concentrated under reduced pressure. The residue was dissolved in ethyl
acetate (300 mL), washed with water (1x50 mL) and brine (1x50 mL); dried over magnesium
sulfate, and concentrated under reduced pressure to a dark amber oil. The crude material
was purified over SiO
2 (20-100 % ethyl acetate/hexanes gradient elution) to afford
(S)-methyl 2-((
tert-butoxycarbonyl)amino)-4-oxobutanoate (12.5 g, 54.1 mmol, 62% crude yield) as a pale
amber oil.
1H NMR (400MHz,
CDCl3) δ ppm 9.76 (s, 1H), 5.41 (br. s., 1H), 4.62 (dt,
J=8.1, 4.4 Hz, 1H), 3.77 (s, 3H), 3.19 - 2.94 (m, 2H), 1.46 (s, 9H).

Part E: (S)-methyl 2-((tert-butoxycarbonyl)amino)-5,5-difluoropent-4-enoate
[0585] A solution of
(S)-methyl 2-((
tert-butoxycarbonyl)amino)-4-oxobutanoate (5.97 g, 25.8 mmol), sodium 2-chloro-2,2-difluoroacetate
(11.8 g, 77.0 mmol), triphenylphosphine (20.3 g, 77.0 mmol), and
N,
N-dimethylformamide (50 mL) was charged to a 500 mL 3-necked flask and heated to 115
°C for 15 min. The resulting mixture was filtered through diatomaceous earth (Celite
®) and concentrated under reduced pressure. The crude material was purified over SiO
2 (5-40 % ethyl acetate/hexanes gradient elution) to afford
(S)-methyl 2-((
tert-butoxycarbonyl)amino)-5,5-difluoropent-4-enoate (0.91 g, 3.43 mmol, 13% yield) as
a colorless oil.
1H NMR (400MHz,
CDCl3) δ ppm 5.25 - 5.06 (br. s., 1H), 4.42 (br. s., 1H), 4.24 - 4.10 (m, 1H), 3.78 (s,
3H), 2.59 (dd,
J=14.4, 6.7 Hz, 1H), 2.51 - 2.31 (m, 1H), 1.47 (s, 9H).

Part F: (S)-tert-butyl (5,5-difluoro-1-hydroxypent-4-en-2-yl)carbamate
[0586] An ambient temperature solution of
(S)-methyl 2-((
tert-butoxycarbonyl)amino)-5,5-difluoropent-4-enoate (1.91 g, 7.20 mmol) in tetrahydrofuran
(25 mL) was treated with lithium borohydride (0.31 g, 14 mmol) and stirred for 1 h.
The resulting solution was cooled to 5 °C, quenched with 0.1 N aqueous hydrochloric
acid (50 mL), and extracted with ethyl acetate (3x25 mL). The pooled organic extracts
were washed with brine (1x20 mL), dried over MgSO
4, and concentrated under reduced pressure. The crude material was purified over SiO
2 (20-100 % ethyl acetate/hexanes gradient elution) to afford
(S)-
tert-butyl (5,5-difluoro-1-hydroxypent-4-en-2-yl)carbamate (1.4 g, 5.90 mmol, 82% yield)
as a colorless oil.
1H NMR (400MHz, CHLOROFORM-d) δ ppm 4.75 (d,
J=6.0 Hz, 1H), 4.35 - 4.05 (m, 1H), 3.82 - 3.51 (m, 3H), 2.46 - 2.16 (m, 3H), 1.47
(s, 9H).

Part G: (S)-tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-5,5-difluoropent-4-en-2-yl)carbamate
[0587] A suspension of 8-chloro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (1.26 g, 4.88 mmol), prepared as in Example 16, Part G,
(S)-
tert-butyl (5,5-difluoro-1-hydroxypent-4-en-2-yl)carbamate (1.39 g, 5.86 mmol), 2-di-
t-butylphosphino-2',4',6'-triisopropylbiphenyl (0.42 g, 0.98 mmol), Pd(OAc)
2 (0.11 g, 0.49 mmol), Cs
2CO
3 (3.18 g, 9.76 mmol), and anhydrous toluene (15 mL) was purged with nitrogen for 10
minutes and heated to 90 °C overnight (15 h). After cooling, the reaction mixture
was filtered through diatomaceous earth (Celite
®), concentrated under reduced pressure and dissolved in ethyl acetate (50 mL). The
organic layer was washed with brine (1x100 mL) and water (1x100 mL); dried over Na
2SO
4 and concentrated under reduced pressure to afford an amber oil. The crude material
was purified over SiO
2 (1-5 % 2M ammonia in methanol/dichloromethane gradient elution) to afford
(S)-
tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-5,5-difluoropent-4-en-2-yl)carbamate (1.04 g, 2.26 mmol,
46% yield) as a tan solid. LC/MS, (ESI)
m/
z 460.0 [(M+H)
+, calcd for C
24H
28F
2N
3O
4, 460.2];
1H NMR (400MHz,
CDCl3) δ ppm 8.59 (d,
J=5.5 Hz, 1H), 8.05 (d,
J=8.8 Hz, 1H), 7.73 (d,
J=5.8 Hz, 1H), 6.83 (dd,
J=8.8, 1.8 Hz, 1H), 6.79 (br. s., 1H), 5.13 - 4.89 (m, 1H), 4.39 - 4.21 (m, 1H), 4.20
- 3.96 (m, 3H), 3.66 (s, 3H), 3.12 (s, 3H), 2.61 - 2.31 (m, 2H), 1.48 (s, 9H).

Part H: (S)-tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-5,5-difluoropent-4-en-2-yl)carbamate
[0588] A solution of
(S)-
tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-5,5-difluoropent-4-en-2-yl)carbamate (1.03 g, 2.24 mmol)
in acetonitrile (22 mL) was treated with
N-bromosuccinimide (0.44 g, 2.5 mmol), heated to 80 °C for 45 min, and then concentrated
under reduced pressure. The crude material was purified over SiO
2 (1-4 % 2M ammonia in methanol/dichloromethane gradient elution) to afford
(S)-
tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-5,5-difluoropent-4-en-2-yl)carbamate (0.81 g, 1.51 mmol,
67% yield) as a white solid. LC/MS, (ESI)
m/
z 537.9 [(M+H)
+, calcd for C
24H
27BrF
2N
3O
4, 538.1];
1H NMR (400MHz,
CDCl3) δ ppm 8.62 (d,
J=5.8 Hz, 1H), 8.22 (s, 1H), 7.65 (d,
J=5.5 Hz, 1H), 6.75 (s, 1H), 5.01 (d,
J=8.3 Hz, 1H), 4.41 - 4.26 (m, 1H), 4.24 - 4.04 (m, 3H), 3.67 (s, 3H), 3.12 (s, 3H),
2.64 - 2.34 (m, 2H), 1.48 (s, 9H).

Part I: (S)-tert-butyl (1-((9-cyano-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-5,5-difluoropent-4-en-2-yl)carbamate
[0589] A suspension of
(S)-
tert-butyl (1-((9-bromo-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-5,5-difluoropent-4-en-2-yl)carbamate (0.48 g, 0.892 mmol),
zinc cyanide (0.115 g, 0.981 mmol), 1,1'-bis(diphenylphosphino)ferrocene (0.074 g,
0.134 mmol), Pd2(dba)3 (0.041 g, 0.045 mmol),
N,
N-dimethylformamide (3 mL), and water (0.3 mL) was charged to a 20 mL pressure rated
vial and bubbled with a stream of nitrogen for 10 minutes. The vial was sealed, purged
of oxygen, and stirred under nitrogen in a pre-heated reaction block at 115 °C overnight.
After cooling, the reaction mixture was diluted with ethyl acetate (35 mL) and filtered
through diatomaceous earth (Celite
®). The filtrate was washed with brine (3x50 mL), dried over sodium sulfate, and concentrated
under reduced pressure. The crude material was purified over SiO
2 (0-4% 2M ammonia in methanol/dichloromethane gradient elution) to afford
(S)-
tert-butyl (1-((9-cyano-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-5,5-difluoropent-4-en-2-yl)carbamate (0.15 g, 0.280 mmol,
32% yield) as a tan solid. LC/MS, (ESI)
m/
z 485.1 [(M+H)
+, calcd for C
25H
27F
2N
4O
4, 485.2];
1H NMR (400MHz,
CDCl3) δ ppm 8.75 (d,
J=5.5 Hz, 1H), 8.45 (s, 1H), 7.81 (d,
J=5.8 Hz, 1H), 7.00 (s, 1H), 4.85 (d,
J=10.0 Hz, 1H), 4.40 - 4.21 (m, 3H), 4.07 (br. s., 1H), 3.80 (s, 3H), 3.17 (s, 3H),
2.62 - 2.52 (m, 1H), 2.49 - 2.38 (m, 1H), 1.49 (s, 9H).

Part J: (S)-8-((2-amino-5,5-difluoropent-4-en-1-yl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c]
[2,7]naphthyridine-9-carbonitrile
[0590] An ambient temperature solution of
(S)-
tert-butyl (1-((9-cyano-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-5,5-difluoropent-4-en-2-yl)carbamate (60 mg, 0.124 mmol)
in methanol (1 mL) was treated with 4M HCl in 1,4-dioxane (1.3 mL, 5.20 mmol) and
held overnight. The resulting solution was concentrated under reduced pressure. The
crude material was purified via preparative LC/MS with the following conditions: Column:
XBridge C18, 19 x 200 mm, 5-µm particles; Mobile Phase A: 5:95 acetonitrile: water
with 10-mM ammonium acetate; Mobile Phase B: 95:5 acetonitrile: water with 10-mM ammonium
acetate; Gradient: 10-50% B over 20 minutes, then a 5-minute hold at 100% B; Flow:
20 mL/min. Fractions containing the desired were combined and concentrated via centrifugal
evaporation to afford
(S)-8-((2-amino-5,5-difluoropent-4-en-1-yl)oxy)-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-9-carbonitrile
(7.6 mg, 0.020 mmol, 16% yield) as a white solid. LC/MS, (ESI)
m/
z 385.3 [(M+H)
+, calcd for C
20H
19F
2N
4O
2, 385.1];
1H NMR (500MHz,
DMSO) δ ppm 8.82 (s, 1H), 8.60 (d,
J=5.5 Hz, 1H), 8.18 (d,
J=5.8 Hz, 1H), 6.97 (s, 1H), 4.74 - 4.59 (m, 1H), 4.22 - 4.05 (m, 2H), 3.62 (s, 3H),
3.19 - 3.10 (m, 1H), 2.93 (s, 3H), 2.36 - 2.25 (m, 1H), 2.19 - 2.08 (m, 1H).
Example 107
(S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-7-fluoro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one
[0591]

Part A: (S)-tert-butyl (1-((9-chloro-7-fluoro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate
[0592] (S)-
tert-butyl (1-((7-fluoro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.08 g, 0.175 mmol), prepared
as described in Example 29, Part G, was subjected to chlorination using NCS to afford
(S)-
tert-butyl (1-((9-chloro-7-fluoro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2 yl)carbamate (80 mg, 0.104 mmol, 60%
crude yield) as semi-solid. The material was carried forward without further purification.
LC/MS (ESI)
m/
e 492.2 [(M+H)
+, calcd for C
25H
32ClFN
3O
4 492.2].

Part B: (S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-7-fluoro-4,6-dimethylbenzo [c][2,7]naphthyridin-5(6H)-one
[0593] (S)-
tert-Butyl (1-((9-chloro-7-fluoro-4,6-dimethyl-5-oxo-5,6-dihydrobenzo[
c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (0.08 g, 0.104 mmol)) was
subjected to deprotection of the Boc group as described in Example 2, Part E. The
crude material was purified via reverse pahse HPLC (10MM ammonium acetate in water/AcCN)
to provide (
S)-8-((2-amino-4-methylpentyl)oxy)-9-chloro-7-fluoro-4,6-dimethylbenzo[
c][2,7]naphthyridin-5(
6H)-one (0.006 g, 0.015 mmol, 14% yield) as off-white solid. LC/MS (ESI)
m/
e 392.2 [(M+H)
+, calcd for C
20H
24ClFN
3O
2 392.1]; LC/MS retention time (LC/MS Method C)
tR = 2.11 min. HPLC retention time (method A):
tR = 8.96 min; HPLC retention time (method B):
tR = 5.15 min.
1H NMR (400MHz, METHANOL-d
4) 8.62 (d,
J=5.8 Hz, 1H), 8.32 (d,
J=2.0 Hz, 1H), 8.12 (d,
J=5.8 Hz, 1H), 4.26 (ddd,
J=9.3, 3.8, 1.0 Hz, 1H), 4.06 (dd,
J=8.7, 7.2 Hz, 1H), 3.87 (d,
J=9.3 Hz, 3H), 3.67 - 3.64 (m, 1H), 3.08 (s, 3H), 1.92 - 1.78 (m, 1H), 1.56 - 1.37
(m, 2H), 1.02 (d,
J=5.3 Hz, 3H), 1.01 (d,
J=5.3 Hz, 3H).
Methods
AAK1 Kinase Assay
[0594] The assays were performed in U-bottom 384-well plates. The final assay volume was
30 µl prepared from 15 µl additions of enzyme and substrates (fluoresceinated peptide
(5-FAM)-Aha-KEEQSQITSQVTGQIGWR-NH2 and ATP) and test compounds in assay buffer (10
mM Tris-HCL pH 7.4, 10 mM MgCl
2, 0.01% Tween-20 and 1.0 mM DTT). The reactions were initiated by the combination
of bacterially expressed, GST-Xa-hAAKI with substrates and test compounds. The reactions
were incubated at room temperature for 3 hours and terminated by adding 60 µl of 35
mM EDTA buffer to each sample. The reactions were analyzed on the Caliper LabChip
3000 (Caliper, Hopkinton, MA) by electrophoretic separation of the fluorescent substrate
and phosphorylated product. Inhibition data were calculated by comparison to EDTA
quenched control reactions for 100% inhibition and vehicle-only reactions for 0% inhibition.
The final concentration of reagents in the assays are ATP, 22 µM; (5-FAM)-Aha-KEEQSQITSQVTGQIGWR-NH2,
1.5 µM; GST-Xa-hAAK1, 3.5 nM; and DMSO, 1.6%. Dose response curves were generated
to determine the concentration required inhibiting 50% of kinase activity (IC
50). Compounds were dissolved at 10 mM in dimethylsulfoxide (DMSO) and evaluated at
eleven concentrations. IC
50 values were derived by non-linear regression analysis.
HEK281 Cell-Based Assay
[0595] HEK293F cells were cultured in media containing DMEM (Gibco, cat. #11965), 10% FBS
(SAFC Biosciences, cat. #12103C), 1X GPS (glutamine, penicillin and streptomycin).
On day one, cells were plated on a 10cm dish so that they are ∼80% confluent at time
of transfection. Roughly 12 million cells were in a 10cm dish at time of transfection.
On day two, each dish was transfected with 48 ug DNA and 144 ul Lipofectamine 2000
(Invitrogen, cat.# 11668-019). The DNA was comprised of a mixture (per 10cm dish)
containing 3 ug AAK1/HA/pIRES (full length human, NCBI accession no. NP_055726.2),
45 µg Flag/AP2MI/pcDNA (full length human), and 1.5 ml OPTI-MEM. The Lipofectamine
2000 is made up of a mixture (per 10cm dish) containing 144 µl Lipofectamine 2000
and 1.5 ml OPTI-MEM. Each mixture was transferred to individual 15ml tubes and incubated
at RT for 5 minutes, and then the two mixes were combined and incubated at RT for
20 minutes. Growth media was then aspirated from each 10cm plate and replaced with
10ml of DMEM+10% FBS (no GPS). Finally, 3 ml DNA/Lipofectamine mix was added to each
10cm dish and mix gently followed by incubate of plate overnight at 37°C and 5% CO
2.
[0596] On day three, compounds were diluted in 100% DMSO at 1000X final concentration, followed
by 3-fold serial dilutions for a total of 5 concentrations tested. Four compounds
were tested per 10cm dish. One ul of each compound dilution was then pipetted into
a deep-well, 96-well plate, followed by addition of 500 µl DMEM + 0.5% FBS into each
well for a 2X final concentration of each compound. Cells were resuspended in a 10cm
dish by simple pipetting (HEK293 cells come off the plate that easy at this point)
and then transferred to a 50 ml conical tube and pelleted by centrifugation at 1000rpm
for 5 min. Cell pellets were then resuspended in 2.75 ml DMEM + 0.5% FBS per 10cm
dish and 100 µl of cell suspension transferred into each well of 96-well TC plate.
Finally, 100 µl of 2X compound diluted in DMEM + 0.5% FBS was then added into wells
containing cell suspension for a 1X final concentration. Plates were then incubated
at 37°C and 5% CO
2 for 3 hours followed by transferring of cell suspensions from each well into 12-tube
PCR strips. The PCR strips were spun in a tip rack at 1000rpm for 5 minutes to pellet
cells and media was then removed by pipetting without disturbing the cell pellet.
[0597] To prepare for Western Blot analysis, cell pellets were resuspend in 40ul 1X LDS-PAGE
sample buffer (Invitrogen, cat.# NP0008) + 2X Halt phophatase and protease inhibitor
cocktail (Thermo Scientific, cat.#1861284), followed by sonicating each with microtip
sonicator set at 5 for 8-10 seconds. Five ul of 10X NuPage Sample Reducing Agent (with
50 mM DTT) was to each sample followed by heat denaturing at 70C for 10 min on PCR
machine. A total of 10µl per sample was loaded into each lane of a 4-20% Tris-Glycine
Criterion 26-well gel (Biorad, cat.# 345-0034) for the phospho-mu2 blot and 10µl per
lane in a 4-12% Bis-Tris (+MES buffer) NuPAGE 26-well gel (Invitrogen, cat.# WG1403BX10)
for the mu2 blot. For controls, 2ng of phospho-mu2 or 20ng mu2/Flag proteins were
loaded in the last well of each gel. After SDS-PAGE, samples on each gel were transferred
to PVDF membrane using an iBlot and membranes were blocked for one hour in TBST +
5% milk, followed by wash 3X for 5-10 min with TBST. Criterion gels were probed with
rabbit anti-phospho-mu2 (1:5000; a rabbit polyclonal antibody produced by New England
Peptide and affinity purified at Lexicon) in TBST + 5% BSA, whereas, NuPAGE gels were
probed with mouse anti-Flag (1:500; Sigma, cat.# F1804) in TBST + 5% milk, and these
primary antibodies were incubated overnight at 4°C on a rocker.
[0598] On day four, Western blots were washed 3X for 5-10 minutes with TBST, probe with
anti-rabbit-HRP (1:2000; BioRad, cat.# 170-6515) or anti-mouse-HRP (1:2000; Biorad,
cat.# 170-6516) in TBST + 5% milk for 1 hour at RT, washed 3X for 10 minutes with
TBST, and developed with ECL reagent (GE Healthcare, cat.# RPN2132) on a Versadoc.
Finally, the camera was set up to take a picture every 30 seconds for 10 minutes and
the best image saved for each blot with no saturated signal (when the signal is saturated,
the bands will be highlighted red). A volume analysis on each band was performed to
obtain density values. Percent inhibition was calculated for each sample by first
normalizing to total Mu2 expression levels and then comparing to 0% and 100% controls.
IC
50 values were then calculated using Excel fitting software.
AAK1 Knockout Mice
[0599] Mice homozygous (-/-) for the disruption of the AAK1 gene were prepared by two methods;
gene trapping and homologous recombination.
[0600] Gene trapping is a method of random insertional mutagenesis that uses a fragment
of DNA coding for a reporter or selectable marker gene as a mutagen. Gene trap vectors
have been designed to integrate into introns or genes in a manner that allows the
cellular splicing machinery to splice vector encoded exons to cellular mRNAs. Commonly,
gene trap vectors contain selectable marker sequences that are preceded by strong
splice acceptor sequences and are not preceded by a promoter. Thus, when such vectors
integrate into a gene, the cellular splicing machinery splices exons from the trapped
gene onto the 5' end of the selectable marker sequence. Typically, such selectable
marker genes can only be expressed if the vector encoding the gene has integrated
into an intron. The resulting gene trap events are subsequently identified by selecting
for cells that can survive selective culture.
[0601] Embryonic stem cells (Lex-1 cells from derived murine strain A129), were mutated
by a process involving the insertion of at least a portion of a genetically engineered
vector sequence into the gene of interest, the mutated embryonic stem cells were microinjected
into blastocysts which were subsequently introduced into pseudopregnant female hosts
and carried to term using established methods.
See, e.g., "
Mouse Mutagenesis", 1998, Zambrowicz et al., eds., Lexicon Press, The Woodlands, TX. The resulting chimeric animals were subsequently bred to produce offspring capable
of germline transmission of an allele containing the engineered mutation in the gene
of interest.
[0602] AAK1-gene disrupted mice were also made by homologous recombination. In this case,
the second coding exon of the murine AAK1 gene (see GenBank Accession Number NM_177762)
was removed by methods known in the art.
See,
e.g., U.S. Patent Nos. 5,487,992,
5,627,059, and
5,789,215.
[0603] Mice homozygous (-/-) for the disruption of the AAK1 gene were studied in conjunction
with mice heterozygous (+/-) for the disruption of the AAK1 gene, and wild-type (+/+)
litter mates. During this analysis, the mice were subject to a medical work-up using
an integrated suite of medical diagnostic procedures designed to assess the function
of the major organ systems in a mammalian subject. Homozygous (-/-) "knockout" mice
were studied in conjunction with their heterozygous (+/-) and wild-type (+/+) litter
mates. Disruption of the AAK1 gene was confirmed by Southern analysis. Expression
of the murine homolog of AAK1 was detected by RT-PCR in murine brain; spinal cord;
eye; thymus; spleen; lung; kidney; liver; skeletal muscle; bone; stomach, small intestine
and colon; heart; adipose; asthmatic lung; LPS liver; blood; banded heart; aortic
tree; prostate; and mammary gland (5 week virgin, mature virgin, 12 DPC, 3 day post-partum
(lactating), 3 day post-weaning (early involution), and 7 day post-weaning (late involution)).
[0604] AAK1 homozygous (-/-) and their wild-type (+/+) littermates were tested using the
formalin paw test in order to assess their acute and tonic nociceptive responses.
For these tests, Automatic Nociception Analyzers (purchased from the Ozaki lab at
University of California, San Diego) were used. A metal band was placed around the
left hind paw of each mouse 30 minutes prior to testing. After the 30-minute acclimation
period, 20 µl of 5% formalin is subcutaneously injected in the dorsal surface of the
left hind paw. Mice were individually housed in cylindrical chambers for 45 minutes.
Fresh 5 % formalin solution was prepared by diluting formaldehyde (Formalde-fresh
20%, Fisher Scientific, Fair Lawn, NJ) with distilled water. Investigatory compounds
were administered 30 minutes prior to formalin injection.
[0605] A computer recorded flinches per minute, total flinches for phase I (acute phase
= first 8 minutes), and total flinches for phase II (tonic phase = time between minutes
20 - 40) through an electromagnetic field.
See Yaksh TL, Ozaki G, McCumber D, Rathbun M, Svensson C, Malkmus S, Yaksh MC. An automated
flinch detesting system for use in the formalin nociceptive bioassay. J Appl Physiol.,
2001; 90:2386-402. As shown in Figure 1, phase 1 and phase 2 data were obtained using homozygous (-/-)
mice females (n = 16), wild-type females (n = 15), homozygous (-/-) mice males (n
= 9), and wild-type males (n = 18). In all groups and in both phases, the AAK1 homozygous
(-/-) mice exhibited significantly less recorded paw flinching than their wild-type
(+/+) littermates.
[0606] Studies of AAK1 knockout mice showed that disruption of the AAK1 gene affects pain
response as measured using the formalin paw test described above. The same test was
used to confirm that the administration of an AAK1 inhibitor can also affect pain
response.
[0607] A compound of the disclosure was tested in this assay at different doses. Gabapentin
and pregabalin were used as positive controls. Results are shown below in Table 2,
wherein the effect of gabapentin at 200 mg/kg is considered a 100% response, the %
response for the other compounds is relative to the 200 mg/kg dose of gabapentin,
"sc" means subcutaneous administration; "po" means oral administration.
Table 2
| Compound |
Dose (m/kg) |
Response |
| Gabapentin |
50 sc |
60% |
| Gabapentin |
200 sc |
100% |
| Pregabalin |
50 sc |
90% |
| Example 14: (S)-8-((2-amino-4-methylpentyl)oxy)-9-fluoro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one |
30 po |
62% |